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.
13（）
A.affirm
B.witness
C.observe
D.approve
参考答案：A
解析：
[解题思路] 考查动词。本题较难。难点在于把一个句子的主语和谓语都划了横线让考生自己填，就必须先选对一个，才能选对另外一个。本空套在as引导的一个定语从句中“as the careers of their elites______”，即“正如他们中的那些精英成就的事业所______的一样”，前文说“他们的智商高于平均水平，同时做出了巨大贡献”，而该定语从句中的“精英的事业”无疑就成为前面观点的具体证据，那么其功能自然就是“证明观点”，因此，只能选出表示“证明”的[A]选项。