单选题
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 (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 chloral 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 strong 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.
【答案解析】[考点] 考查固定搭配。 at the thought of意为“一想到……”；at the sight of意为“一看见”；at the cost of意为“以……的代价”；at the risk of意为“冒着……的危险”。比较四个选项可以得出，at the thought of最符合句意，此处意为“一想到他即将要做的……”，本题选A。
【答案解析】[考点] 考查名词词义辨析。 The latter与The former对应，都是在讲原因，前者归因于重视教育的优良传统，后者则被认为是遗传隔离的结果。development意为“发展”；origin意为“起源”；consequence意为“结果”；instrument意为“工具；器具”，可见C项为正确答案。