Few scientific fields are as full of risk as that of research into human intelligence. The two questions that (1) over and over again are "is it a result of nature or nurture" and "does race make a difference"
Making (2) comments about the second question can be a (3) move, as James Watson, a co-discoverer of DNA structure, recently found. He suggested that he was " (4) about the prospect of Africa" (5) "all our social policies are based on the fact that their intelligence is the same as ours (white people) (6) all the testing says not really". Such (7) by Dr. Watson are not merely (8) , they are scientifically weird. If the term (9) has any useful scientific meaning, then Africa, the continent where modern humanity began, is most racially diverse. The resulting (10) among the public forced Dr. Watson to leave his laboratory.
(11) , the study of the first question (12) between intelligence and genetics— has some wiser practitioners. One of them, Terrie Moffitt, of King’s College, has just (13) a project judging the relative importance of nature and nurture. Dr. Moffitt’s team (14) the effect on intelligence of breastfeeding, but in a genetic context. Previous studies have shown that breastfed children are more intelligent, (15) about six IQ points, than those given baby formulas.
The team, however, (16) the involvement of a gene called FADS2, which comes in two varieties, known as C and G. The researchers (17) if these two varieties interacted differently with breast milk. (18) on data from two groups of people, they found that the intelligence increase associated with breastfeeding only happened to people having (19) at least one copy of the C variety. The effect did not. (20) on the social classes or IQs of the parents.
18（）
A.Deciding
B.Acting
C.Drawing
D.Reflecting
参考答案：C
解析：
[试题考点] 上下文语意关系和固定搭配。
[解题思路] 本句空格所在部分为句子的状语，其后主句为they found that...。该句意为“______两组人群的数据，他们发现……”。由此可推知，“数据”是研究人员做出判断的依据，四个选项都可以与空格后的介词on搭配，但只有选项[C]drawing与on搭配符合文意，drawing on意为“利用；使用”，代入文中意为“利用两组人群的数据”。
[干扰排除] 选项[A]decide (on)意为“(就某事)作出决定”，选项[B]act (on)意为“对……起作用；按……行事”，选项[D]reflect (on)意为“思考；反省”，代入文中，都无法表示“研究者根据这些数据得出某个结论”的含义。