Cryto Giá

Đối với nguyên tử hiđrô gọi r0 là bán kính Bo bán kính quỹ đạo dừng có thể có giá trị nào

Trong nguyên tử hidro, bán kính Bo là
. Bán kính quỹ đạo dừng N là

Đáp án và lời giải

Đáp án:C

Lời giải:

Đáp án C

Câu hỏi thuộc đề thi sau. Bạn có muốn thi thử?

Bài tập trắc nghiệm 60 phút Mẫu nguyên tử Bo - Lượng tử ánh sáng - Vật Lý 12 - Đề số 3

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Một số câu hỏi khác cùng bài thi.

Theo thuyết Bo ,bán kính quỹ đạo thứ nhất của electron trong nguyên tử hidro là r0 = 5,3. 10-11 m, cho hằng số điện k = 9. 109 Nm2/C2. Hãy xác định vận tốc góc của electron chuyển động tròn đều quanh hạt nhân trên quỹ đạo này.
Theo mẫu nguyên tử Bo, trong nguyên tử hiđrô bán kính Bo là
, chuyển động của êlectron quanh hạt nhân là chuyển động tròn đều. Tốc độ góc của êlectron trên quỹ đạo O là
, tốc độ góc của êlectron trên quỹ đạo M là
. Hệ thức đúng l
Trong nguyên tử hidro, bán kính Bo là
. Bán kính quỹ đạo dừng N là
Trong quang phổ vạch của hiđrô, bước sóng của vạch thứ nhất trong dãy Laiman và vạch thứ nhất trong dãy Banme lần lượt là
và
. Bước sóng của vạch thứ hai trong dãy Laiman bằng:
Dãy Pa-sen trong quang phổ vạch Hiđro ứng với sự dịch chuyển của các êlectron từ các quỹ đạo dừng có năng lượng cao về quỹ đạo.
Biết bước sóng ứng với bốn vạch trong vùng ánh sáng nhìn thấy của quang phổ hidro là λα = 0,656 μm, λβ = 0,486 μm; λγ = 0,434μm ; λδ = 0,410 μm. Bước sóng khi nguyên tử hidro chuyển từ mức năng lượng kích thích thứ 3 về mức năng lượng kích thích thứ 2 bằng:
Mức năng lượng trong nguyên tử hiđrô được xác định bằng biểu thức E = -
[eV] với n€ N*, trạng thái cơ bản ứng với n = 1. Một đám khí hiđrô đang ở trạng thái kích thích và electron đang ở quĩ đạo dừng N. Tỉ số giữa bước sóng dài nhất và ngắn nhất mà đám khí trên có thể phát ra khi chuyển về trạng thái dừng có mức năng lượng thấp hơn là ?
Trongquangphổvạchcủanguyêntửhiđro, vạchứngvớisựdịchchuyểncủa electron từquỹđạo M vềquỹđạo K là:
, vạchứngvớibướcsóngdàinhấttrongdãy Ban-me là
. Bướcsóngdàinhấtcủadãy Lai-man là:
Khi nguyên tử hidro phát bức xạ có bước sóng 486 nm thì năng lượng của nguyên tử hidro đã giảm một lượng bằng:
Biết bán kính Bo là r0 = 5,3. 10–11 m. Bán kính quỹ đạo dừng M trong nguyên tử hidro là:
Vạch quang phổ có tần số nhỏ nhất trong dãy Banme là tần số
. Vạch quang phổ có tần số nhỏ nhất trong dãy Laiman là tần số
. Vạch quang phổ trong dãy Laiman sát với vạch có tần số
sẽ có tần số là:
Năng lượng của trạng thái dừng của nguyên tử H2 xác định bằng công thức
. Biết tỷ số giữa bước sóng ngắn nhất và dài nhất tương ứng trong dãy Laiman và Banlme là a và B. Tỷ số a/b là:
Nguyên tử hiđrô chuyển từ trạng thái cơ bản lên trạng thái dừng mà electron chuyển động trên quỹ đạo O. Tính số vạch quang phổ mà nguyên tử có thế phát ra khi chuyển về các trạng thái có năng lượng thấp hơn.
Nguyên tử Hiđro tồn tại trên các trạng thái dừng có mức năng lượng xác định En = -13,6/n2 MeV, n = 1, 2, 3,… Một đám khí hidro hấp thụ năng lượng chuyển lên trạng thái dừng có năng lượng cao nhất là E3. Tỉ số giữa bước sóng dài nhất và ngắn nhất mà đám khí trên có thể phát ra là:
Xét nguyên tử hiđrô theo mẫu nguyên tử Bo. Khi electron trong nguyên tử chuyển động tròn đều trên quỹ đạo dừng M thì có tốc độ v[m/s]. Biết bán kính Bo là r0. Nếu electron chuyển động trên một quỹ đạo dừng với thời gian chuyển động hết một vòng là
[s] thì electron này đang chuyển động trên quỹ đạo:
Các vạch trong dãy Banme thuộc
Trong nguyên tử hiđrô, bán kính Bo là r0 = 5,3. 10-11m. Ở một trạng thái kích thích của nguyên tử hiđrô, êlectron chuyển động trên quỹ đạo dừng có bán kính là r = 2,12. 10-10m. Quỹ đạo đó có tên gọi là quỹ đạo dừng
Xét nguyên tử hiđrô theo mẫu nguyên tử Bo, trong các quỹ đạo dừng của êlectron có hai quỹ đạo có bán kính
và
. Biết
, trong đó
là bán kính Bo. Giá trị
gần nhất với giá trị nào sau đây?
Trong nguyên tử hiđrô, bán kính Bo là ro = 5,3.10-11 m. Ở một trạng thái kích thích của nguyên tử hiđrô, êlectron chuyển động trên quỹđạo dừng có bán kính là r = 19,08.10-10 m. Quỹđạo dừng đó có tên gọi là:
Theo thuyết Bo [Bohr], các mức năng lượng của các trạng thái dừng của nguyên tử hiđrô được xác định bằng biểu thức En= −13,6/n2 với n = 1, 2, 3 …. Giả sử một đám nguyên tử hiđrô đang ở trạng thái cơ bản thì được kích thích bởi một chùm bức xạ để đám nguyên tử này có thể phát ra tất cả các vạch trong quang phổ phát xạ của nguyên tử hiđrô. Tần số tối thiểu của bức xạ này gần bằng
Cho bước sóng vạch quang phổ khi electron chuyển từ quỹ đạo dừng N về L là 0,487 μm, c = 3. 108 m/s, h =6,625. 10–34 J. s, |e| = 1,6. 10–19
Trong nguyên tử hiđrô, electron chuyển từ quỹ đạo L [n = 2] lên quỹ đạo N [n = 4]. Điều này xảy ra là do
Muốn quang phổ vạch của nguyên tử hiđrô chỉ phát ra 3 vạch thì phải kích thích nguyên tử hiđrô đến mức năng lượng.
Bước sóng dài nhất trong dãy Banme là 0,6560µm. Bước sóng dài nhất trong dãy Laiman là 0,1220µm. Bước sóng dài thứ hai của dãy Laiman là:
Dãy Pa-sen trong quang phổ vạch của hiđrô ứng với sự dịch chuyển của các electron từ các quỹ đạo dừng có năng lượng cao về quỹ đạo
Trong nguyên tử hiđrô , bán kính Bo là r0= 5,3.10-11m. Bán kính quỹ đạo dừng N là :
Đối với nguyên tử hiđrô, khi êlectron chuyển từ quỹ đạo M về quỹ đạo K thì nguyên tử phát ra phôtôn có bước sóng 0,1026 µm. Lấy h = 6,625. 10–34 J. s, |e| = 1,6. 10–19 C và c = 3. 108 m/s. Năng lượng của phôtôn này bằng:
Đám nguyên tử hiđrô ở mức năng lượng kích thích O, khi chuyển xuống mức năng lượng thấp sẽ có khả năng phát ra số vạch tối đa thuộc dãy Banme là:
Trong nguyên tử hiđrô, êlectrôn từ quỹ đạo L chuyển về quỹ đạo K có năng lượng EK = –13,6 eV. Bước sóng bức xạ phát ra bằng là λ = 0,1218 µm. Mức năng lượng ứng với quỹ đạo L bằng
Electron trong nguyên tử hidro chuyển từ quỹ đạo dừng có mức năng lượng lớn về quỹ đạo dừng có mức năng lượng nhỏ hơn thì vận tốc của nó tăng 4 lần. Electron đã chuyển từ quỹ đạo:
Mức năng lượng nguyên tử Hidro ở trạng thái dừng có biểu thức:
với
. Khi kích thích nguyên tử Hidro ở trạng thái cơ bản bằng việc hấp thụ một photon có năng lượng thích hợp, bán kính quỹ đạo dừng của electron tăng thêm 9 lần. Bước sóng lớn nhât của bức xạ mà nguyên tử có thể phát ra là ?
Một đám nguyên tử hydro đang ở trạng thái dừng có mức năng lượng E0 [n = 5 ] khi chúng chuyển về trạng thái cơ bản có thể phát ra nhiều nhất bao nhiêu bức xạ đơn sắc?
Cho bánkínhquỹđạodừngcủa electron trongnguyêntửhidrô ở trạngtháicơbảnlà 5,3.10-11 m. Nếubánkínhquỹđạodừngcủa electron trongnguyêntửhidrôlà 2,12 A0thì electron đangchuyểnđộngtrênquỹđạonào ?
Trong nguyên tử Hidro, khi electron chuyển động trên quĩ đạo K có bán kính
thì electron có vận tốc [Cho khối lượng và độ lớn điện tích của electron lần lượt là
= 9,1.10-31kg; e = l,6.10-19C]:
Phát biểu nào sau đây ℓà đúng khi nói về mẫu nguyên tử Bo?
Cho bán kính quỹ đạo dừng của electron trong nguyên tử hidrô ở trạng thái cơ bản là 5.3.10-11 m. Nếu bán kính quỹ đạo dừng của electron trong nguyên tử hidrô là 2,12
thì electron đang chuyển động trên quỹ đạo nào ?
Chiều dài 1,484nm:
Xét nguyên tử hiđrô theo mẫu nguyên tử Bo. Electron trong nguyên tử chuyển từ quỹ đạo dừng m1 về quỹ đạo dừng m2 thì bán kính giảm 27 ro [ro là bán kính Bo], đồng thời động năng của êlectron tăng thêm 300%. Bán kính của quỹ đạo dừng m1 có giá trị gần nhất với giá trị nào sau đây?
Khi êlectron ở quỹ đạo dừng thứ n thì năng lượng của nguyên tử hiđrô được tính theo công thức - [eV] [n = 1, 2, 3,…]. Khi êlectron trong nguyên tử hiđrô chuyển từ quỹ đạo dừng n = 3 sang quỹ đạo dừng n = 2 thì nguyên tử hiđrô phát ra phôtôn ứng với bức xạ có bước sóng bằng
Khi nguyên tử hidro phát bức xạ có bước sóng 486 nm thì năng lượng của nguyên tử hidro đã giảm một lượng bằng:
Trong nguyên tử Hidro, khi electron chuyển động trên quĩ đạo K có bán kính
thì electron có vận tốc [Cho khối lượng và độ lớn điện tích của electron lần lượt là
= 9,1.10-31kg; e = l,6.10-19C]:

Một số câu hỏi khác có thể bạn quan tâm.

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50:

Milpa Alta is a region of twelve villages and towns to the south of Mexico City. In Milpa Alta, traditions are still very important and one of the most famous traditional events is a community meal. It takes place every Christmas and is called La Rejunta. More than a meal, it’s a feast, where about sixty thousand tamales and fifteen thousand litres of hot chocolate are made and consumed. Tamales are made from corn. They are typical of the region: the name Milpa Alta means "High cornfield". The feast is offered to the people who go on the long walk to El Señor de Chalma about 80 kilometers away. It’s an important event on the religious calendar for local people and as many as 20,000 people take part.

The planning and organisation of La Rejunta takes the whole year. Every year, different people are given the job of majordomo, which means they’re responsible for organising the meal. There’s a waiting list for the opportunity to do this and currently the next available year is 2046. This year’s majordomos are Virginia Meza Torres and her husband Fermín Lara Jiménez, who put their names on the list 14 years ago.

One year before the meal, men go to the forest and collect wood that they store near the home of the majordomo. It has to be dry when it’s used to make the cooking fires. Local farmers grow most of the corn, meat and vegetables that are needed as ingredients. In the week before the feast, hundreds of volunteers arrive to help with the preparation and the cooking. No instant or ready-made foods are allowed. Amazingly, everyone seems to know what they have to do. On the day of the feast, the majordomos and others have stayed up all night cooking. Fermin is in charge of the numbers–making sure there are enough tamales for everyone.

For the people of Milpa Alta, eating together is one of their most important traditions. One woman, Josefina García Jiménez, explains that sitting together at the table is like a glue that keeps people together. "It feels like I am passing down a tradition, and when they are adults, they will remember what I have done. Here we have time to cook, time to think about the ingredients, time to show our kids through cooking that we love them." The time that everybody stays at the table after the meal has finished is just as important as the food.

They talk, tell stories and laugh together. At Christmas, La Rejunta is a giant version of a family meal.

Question 50:According to the last paragraph, the important thing about family meals is _____________.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50:

Milpa Alta is a region of twelve villages and towns to the south of Mexico City. In Milpa Alta, traditions are still very important and one of the most famous traditional events is a community meal. It takes place every Christmas and is called La Rejunta. More than a meal, it’s a feast, where about sixty thousand tamales and fifteen thousand litres of hot chocolate are made and consumed. Tamales are made from corn. They are typical of the region: the name Milpa Alta means "High cornfield". The feast is offered to the people who go on the long walk to El Señor de Chalma about 80 kilometers away. It’s an important event on the religious calendar for local people and as many as 20,000 people take part.

The planning and organisation of La Rejunta takes the whole year. Every year, different people are given the job of majordomo, which means they’re responsible for organising the meal. There’s a waiting list for the opportunity to do this and currently the next available year is 2046. This year’s majordomos are Virginia Meza Torres and her husband Fermín Lara Jiménez, who put their names on the list 14 years ago.

One year before the meal, men go to the forest and collect wood that they store near the home of the majordomo. It has to be dry when it’s used to make the cooking fires. Local farmers grow most of the corn, meat and vegetables that are needed as ingredients. In the week before the feast, hundreds of volunteers arrive to help with the preparation and the cooking. No instant or ready-made foods are allowed. Amazingly, everyone seems to know what they have to do. On the day of the feast, the majordomos and others have stayed up all night cooking. Fermin is in charge of the numbers–making sure there are enough tamales for everyone.

For the people of Milpa Alta, eating together is one of their most important traditions. One woman, Josefina García Jiménez, explains that sitting together at the table is like a glue that keeps people together. "It feels like I am passing down a tradition, and when they are adults, they will remember what I have done. Here we have time to cook, time to think about the ingredients, time to show our kids through cooking that we love them." The time that everybody stays at the table after the meal has finished is just as important as the food.

They talk, tell stories and laugh together. At Christmas, La Rejunta is a giant version of a family meal.

Question 49:Fermin _________.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

American humor and American popular heroes were born together. The first popular heroes of the new nation were comic heroes, and the first popular humor of the new nation was the antics of its hero-clowns.

The heroicand the comic were combined in novel American proportions in popular literature.The heroic themes are obvious enough and not much different from those in the legends of other times andplaces: Achilles, Beowulf, Siegfried, Roland, and King Arthur. The American Davy Crockett legends repeat thefamiliar pattern of the old world heroic story: the pre-eminence of a mighty hero whose fame in myth has atenuous basis in fact; the remarkable birth and precocious strength of the hero; single combats in which hedistinguished himself againstantagonists, both man and beast; vows and boasts; pride of the hero in hisweapons, his dog, and his woman.

Davy Crockett conquered man and beast with a swaggering nonchalance. He overcame animals by force ofbody and will. He killed four wolves at the age of six. He hugged a bear to death; he killed a rattlesnake with histeeth. He mastered the forces of nature. Crockett's most famous naturalexploitwas saving the earth on the coldest day in history. First, he climbed a mountain to determine the trouble. Then he rescued all creation bysqueezing bear-grease on the earth's frozen axis and over the sun's icy face. He whistled, "Push along, keepmoving!" The earth gave a grunt and began moving.

Neither the fearlessness nor the bold huntsman'sprowesswas peculiarly American. Far more distinctivewas the comic quality, all heroes are heroic; few are also clowns. What made the American popular hero heroicalso made him comic. "May be", said Crockett, "you'll laugh at me and not at my book". The ambiguity of Americanlife and the vagueness which laid the continent open to adventure, which made the land a rich storehouse of the unexpected, which kept vocabulary ungoverned and the language fluid----this sameambiguitysuffused both theCrockett legends were never quite certain whether to laugh or to applaud, or whether what they saw and heardwas wonderful, awful or ridiculous.

Question 46: Davy Crockett is an example of _______.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

American humor and American popular heroes were born together. The first popular heroes of the new nation were comic heroes, and the first popular humor of the new nation was the antics of its hero-clowns.

The heroicand the comic were combined in novel American proportions in popular literature.The heroic themes are obvious enough and not much different from those in the legends of other times andplaces: Achilles, Beowulf, Siegfried, Roland, and King Arthur. The American Davy Crockett legends repeat thefamiliar pattern of the old world heroic story: the pre-eminence of a mighty hero whose fame in myth has atenuous basis in fact; the remarkable birth and precocious strength of the hero; single combats in which hedistinguished himself againstantagonists, both man and beast; vows and boasts; pride of the hero in hisweapons, his dog, and his woman.

Davy Crockett conquered man and beast with a swaggering nonchalance. He overcame animals by force ofbody and will. He killed four wolves at the age of six. He hugged a bear to death; he killed a rattlesnake with histeeth. He mastered the forces of nature. Crockett's most famous naturalexploitwas saving the earth on the coldest day in history. First, he climbed a mountain to determine the trouble. Then he rescued all creation bysqueezing bear-grease on the earth's frozen axis and over the sun's icy face. He whistled, "Push along, keepmoving!" The earth gave a grunt and began moving.

Neither the fearlessness nor the bold huntsman'sprowesswas peculiarly American. Far more distinctivewas the comic quality, all heroes are heroic; few are also clowns. What made the American popular hero heroicalso made him comic. "May be", said Crockett, "you'll laugh at me and not at my book". The ambiguity of Americanlife and the vagueness which laid the continent open to adventure, which made the land a rich storehouse of the unexpected, which kept vocabulary ungoverned and the language fluid----this sameambiguitysuffused both theCrockett legends were never quite certain whether to laugh or to applaud, or whether what they saw and heardwas wonderful, awful or ridiculous.

Question 47: In paragraph 3, the author mentions a story in which Davy Crockett _______.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

American humor and American popular heroes were born together. The first popular heroes of the new nation were comic heroes, and the first popular humor of the new nation was the antics of its hero-clowns.

The heroicand the comic were combined in novel American proportions in popular literature.The heroic themes are obvious enough and not much different from those in the legends of other times andplaces: Achilles, Beowulf, Siegfried, Roland, and King Arthur. The American Davy Crockett legends repeat thefamiliar pattern of the old world heroic story: the pre-eminence of a mighty hero whose fame in myth has atenuous basis in fact; the remarkable birth and precocious strength of the hero; single combats in which hedistinguished himself againstantagonists, both man and beast; vows and boasts; pride of the hero in hisweapons, his dog, and his woman.

Davy Crockett conquered man and beast with a swaggering nonchalance. He overcame animals by force ofbody and will. He killed four wolves at the age of six. He hugged a bear to death; he killed a rattlesnake with histeeth. He mastered the forces of nature. Crockett's most famous naturalexploitwas saving the earth on the coldest day in history. First, he climbed a mountain to determine the trouble. Then he rescued all creation bysqueezing bear-grease on the earth's frozen axis and over the sun's icy face. He whistled, "Push along, keepmoving!" The earth gave a grunt and began moving.

Neither the fearlessness nor the bold huntsman'sprowesswas peculiarly American. Far more distinctivewas the comic quality, all heroes are heroic; few are also clowns. What made the American popular hero heroicalso made him comic. "May be", said Crockett, "you'll laugh at me and not at my book". The ambiguity of Americanlife and the vagueness which laid the continent open to adventure, which made the land a rich storehouse of the unexpected, which kept vocabulary ungoverned and the language fluid----this sameambiguitysuffused both theCrockett legends were never quite certain whether to laugh or to applaud, or whether what they saw and heardwas wonderful, awful or ridiculous.

Question 44: Which of the following is NOT mentioned as a heroic theme?
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

American humor and American popular heroes were born together. The first popular heroes of the new nation were comic heroes, and the first popular humor of the new nation was the antics of its hero-clowns.

The heroicand the comic were combined in novel American proportions in popular literature.The heroic themes are obvious enough and not much different from those in the legends of other times andplaces: Achilles, Beowulf, Siegfried, Roland, and King Arthur. The American Davy Crockett legends repeat thefamiliar pattern of the old world heroic story: the pre-eminence of a mighty hero whose fame in myth has atenuous basis in fact; the remarkable birth and precocious strength of the hero; single combats in which hedistinguished himself againstantagonists, both man and beast; vows and boasts; pride of the hero in hisweapons, his dog, and his woman.

Davy Crockett conquered man and beast with a swaggering nonchalance. He overcame animals by force ofbody and will. He killed four wolves at the age of six. He hugged a bear to death; he killed a rattlesnake with histeeth. He mastered the forces of nature. Crockett's most famous naturalexploitwas saving the earth on the coldest day in history. First, he climbed a mountain to determine the trouble. Then he rescued all creation bysqueezing bear-grease on the earth's frozen axis and over the sun's icy face. He whistled, "Push along, keepmoving!" The earth gave a grunt and began moving.

Neither the fearlessness nor the bold huntsman'sprowesswas peculiarly American. Far more distinctivewas the comic quality, all heroes are heroic; few are also clowns. What made the American popular hero heroicalso made him comic. "May be", said Crockett, "you'll laugh at me and not at my book". The ambiguity of Americanlife and the vagueness which laid the continent open to adventure, which made the land a rich storehouse of the unexpected, which kept vocabulary ungoverned and the language fluid----this sameambiguitysuffused both theCrockett legends were never quite certain whether to laugh or to applaud, or whether what they saw and heardwas wonderful, awful or ridiculous.

Question 45: The word “antagonists” could be best replaced by _______.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

Walt Disney was born in 1901 in Chicago, but soon moved to a small farm near Marceline, Missouri. From this rural and rather humble beginning, he later became one of the most famous and beloved motion-picture producers in history. Although he died in 1966, his name and artistic legacy continue to influence the lives of millions of people throughout the world.

After several years of barely making ends meet as a cartoon artist operating from his Los Angeles garage, Disney had his first success in 1928, with his release of a Mickey Mouse cartoon. Throughout the next decade, he continued to produce a number of cartoons, and develop more of his highly profitable and enduring creations, such as Donald Duck and Pluto. In the late 1930s, he issued a full-length cartoon film. Snow White became an instant commercial and critical success. This was only the first of many films, both animated and not, produced by Disney and his studio.

But as renowned as Disney name is for cartoons and movies, it is probably best known for a string of spectacular amusement and theme parks. Starting with California's Disneyland in 1955 and culminating with the fantastically successful Disney World and EPCOT Center in Florida, Disney became a household name. In recent years, the theme park concept became international, with openings in Tokyo and Paris. With the continuing success of Disney, the creation of future theme park is under discussion.

Question 42: In future years it is most likely that _______.
Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct answers:

American humor and American popular heroes were born together. The first popular heroes of the new nation were comic heroes, and the first popular humor of the new nation was the antics of its hero-clowns.

The heroicand the comic were combined in novel American proportions in popular literature.The heroic themes are obvious enough and not much different from those in the legends of other times andplaces: Achilles, Beowulf, Siegfried, Roland, and King Arthur. The American Davy Crockett legends repeat thefamiliar pattern of the old world heroic story: the pre-eminence of a mighty hero whose fame in myth has atenuous basis in fact; the remarkable birth and precocious strength of the hero; single combats in which hedistinguished himself againstantagonists, both man and beast; vows and boasts; pride of the hero in hisweapons, his dog, and his woman.

Davy Crockett conquered man and beast with a swaggering nonchalance. He overcame animals by force ofbody and will. He killed four wolves at the age of six. He hugged a bear to death; he killed a rattlesnake with histeeth. He mastered the forces of nature. Crockett's most famous naturalexploitwas saving the earth on the coldest day in history. First, he climbed a mountain to determine the trouble. Then he rescued all creation bysqueezing bear-grease on the earth's frozen axis and over the sun's icy face. He whistled, "Push along, keepmoving!" The earth gave a grunt and began moving.

Neither the fearlessness nor the bold huntsman'sprowesswas peculiarly American. Far more distinctivewas the comic quality, all heroes are heroic; few are also clowns. What made the American popular hero heroicalso made him comic. "May be", said Crockett, "you'll laugh at me and not at my book". The ambiguity of Americanlife and the vagueness which laid the continent open to adventure, which made the land a rich storehouse of the unexpected, which kept vocabulary ungoverned and the language fluid----this sameambiguitysuffused both theCrockett legends were never quite certain whether to laugh or to applaud, or whether what they saw and heardwas wonderful, awful or ridiculous.

Question 43: What is the main point the author makes in the passage?
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions.

Walt Disney was born in 1901 in Chicago, but soon moved to a small farm near Marceline, Missouri. From this rural and rather humble beginning, he later became one of the most famous and beloved motion-picture producers in history. Although he died in 1966, his name and artistic legacy continue to influence the lives of millions of people throughout the world.

After several years of barely making ends meet as a cartoon artist operating from his Los Angeles garage, Disney had his first success in 1928, with his release of a Mickey Mouse cartoon. Throughout the next decade, he continued to produce a number of cartoons, and develop more of his highly profitable and enduring creations, such as Donald Duck and Pluto. In the late 1930s, he issued a full-length cartoon film. Snow White became an instant commercial and critical success. This was only the first of many films, both animated and not, produced by Disney and his studio.

But as renowned as Disney name is for cartoons and movies, it is probably best known for a string of spectacular amusement and theme parks. Starting with California's Disneyland in 1955 and culminating with the fantastically successful Disney World and EPCOT Center in Florida, Disney became a household name. In recent years, the theme park concept became international, with openings in Tokyo and Paris. With the continuing success of Disney, the creation of future theme park is under discussion.

Question 40: The word “renowned” in bold in paragraph 3 is closest in meaning to _______.
Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions:

Walt Disney was born in 1901 in Chicago, but soon moved to a small farm near Marceline, Missouri. From this rural and rather humble beginning, he later became one of the most famous and beloved motion-picture producers in history. Although he died in 1966, his name and artistic legacy continue to influence the lives of millions of people throughout the world.

After several years of barely making ends meet as a cartoon artist operating from his Los Angeles garage, Disney had his first success in 1928, with his release of a Mickey Mouse cartoon. Throughout the next decade, he continued to produce a number of cartoons, and develop more of his highly profitable and enduring creations, such as Donald Duck and Pluto. In the late 1930s, he issued a full-length cartoon film. Snow White became an instant commercial and critical success. This was only the first of many films, both animated and not, produced by Disney and his studio.

But as renowned as Disney name is for cartoons and movies, it is probably best known for a string of spectacular amusement and theme parks. Starting with California's Disneyland in 1955 and culminating with the fantastically successful Disney World and EPCOT Center in Florida, Disney became a household name. In recent years, the theme park concept became international, with openings in Tokyo and Paris. With the continuing success of Disney, the creation of future theme park is under discussion.

Question 41: It can be inferred from the passage that _______.