[单项选择]The first part of the 20th century saw more great inventions.
A. 这是20世纪前半期的第一批伟大的发明。
B. 20世纪前半期有更多伟大的发明。
C. 这是20世纪更多伟大发明中的第一部分。
D. 20世纪前半期人们看见了更多伟大的发明。

[单项选择]The middle part of the 20th century brought new ways to help people get over diseases.
A. 20世纪中叶，人们找到了治疗疾病的新途径。
B. 20世纪中叶带来了帮助人们克服疾病的新办法。
C. 20世纪中叶给人们带来了各种新的疾病。
D. 20世纪中叶人们在路上得到了各种新的疾病。

[单项选择]During an earthquake, the great part of damage and loss of life has been______ collapse of buildings and the effect of rockslides, floods, disease, and other phenomena resulting from earthquakes, rather than from the quakes themselves.
A. due to
B. owing to
C. by reason of
D. on account of

[单项选择]When the foreign tourist saw the Great Wall, he said" ______!"

[单项选择]During the first half of the twentieth century, the average American household was ______ by the introduction of a group of machines that profoundly altered the daily lives of housewives.


A. transformed
B. transferred
C. transmitted
D. transported

[单项选择]In the first decades of the twentieth century, the individual gene could not be seen, but could be worked with fruitfully.
A. blindly
B. completely
C. productively
D. carefully

[单项选择]In the twenty-first century, American's attitude toward remarried people will be（）
A. critical
B. suspicious
C. fussy
D. approving

[单项选择]By the first decade of the 21st century, international commercial air traffic is expected ______beyond today's levels.
A. to have extended
B. to be extending
C. being extended
D. having been extended

[单项选择]

By the first century A. D., historians say, the Chinese had some knowledge of the winds and currents of the Pacific. When weather prevented the Chinese from navigating by the sky their mariners(水手) used magnetized(磁化) needles to guide them. Because the sailors had no level surface on their rocking ship, they floated the needle in a shallow bowl of water, and the compass that guided explorers to day was born.
Between 1450 and 1433, Emperor Chu Ti’s Treasure Fleet of the Dragon Throne ruled the entire south Pacific and the Indian Ocean, collecting gifts and tributes (贡品) for the Emperor throughout a territory that ranges from Korea and Japan to Eastern coast of Africa. The Admiral Cheng Ho began the first of seven voyages in 1405. The purpose of the first voyage was to hurt the former emperor who had been dethroned and escaped. The admiral’s fleet, which was made up of 62 large junks and 255 smaller ships, recaptured the deposed emperor and also defeated
A. Cheng Ho died on the way of his last voyage
B. Cheng Ho ended his seventh voyage in 1433
C. the disappearing of China's economic domination of the South Pacific led to Cheng Ho's death
D. it took Cheng Ho 30 years to visit 37 countries