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问题 选择题

造成我国旱涝灾害频繁的主要原因是

A．夏季风的不稳定性

B．冬季风的不稳定性

C．地势西高东低

D．南北跨纬度度大

答案

答案：A

题目分析：造成我国旱涝灾害频繁的主要原因是夏季风的不稳定性，夏季风强，来得早退得晚，降水多，洪涝，夏季风弱，来得晚退得早，降水少，干旱。

点评：本题的关键是理解夏季风与我国降水的关系。本题还可以考查我国季风的风向、类型、特征，影响下的降水时空分布等知识。

单项选择题 A1/A2型题

下列哪项不是HBV感染的高危人群（）。

A.接种过乙肝疫苗且存在抗体者

B.多个性伴侣者

C.接触血液的医务工作者

D.血友病患者

E.HBsAg阳性母亲的新生儿
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单项选择题

The idea that some groups of people may be more intelligent than others is one of those hypotheses that dare not speak its name. But Gregory Cochran is (1) to say it anyway. He is that (2) bird, a scientist who works independently (3) any institution. He helped popularize the idea that some diseases not (4) thought to have a bacterial cause were actually infections, which aroused much controversy when it was first suggested.

(5) he, however, might tremble at the (6) of what he is about to do. Together with another two scientists, he is publishing a paper which not only (7) that one group of humanity is more intelligent than the others, but explains the process that has brought this about. The group in (8) are a particular people originated from central Europe. The process is natural selection.

This group generally do well in IQ test, (9) 12-15 points above the (10) value of 100, and have contributed (11) to the intellectual and cultural life of the West, as the (12) of their elites, including several world-renowned scientists, (13) . They also suffer more often than most people from a number of nasty genetic diseases, such as breast cancer. These facts, (14) , have previously been thought unrelated. The former has been (15) to social effects, such as a p tradition of (16) education. The latter was seen as a (an) (17) of genetic isolation. Dr. Cochran suggests that the intelligence and diseases are intimately (18) . His argument is that the unusual history of these people has (19) them to unique evolutionary pressures that have resulted in this (20) state of affairs.

19（）

A.limited

B.subjected

C.converted

D.directed
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