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.

Questions：
1. A. selected B. prepared C. obliged D. pleased
2. A. unique B. particular C. special D. rare
3. A. of 　　B. with 　　　C. in　　　D. against

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