例40　This preference for exogamy, Gutman suggests, may have derived from West African rules governing marriage, which, though they differed from one tribal group to another, involved some kind of prohibition against unions with close kin.

【结构分析】主语中心语是This preference for exogamy，谓语动词是may have derived from，宾语是West African rules, governing marriage这个分词做定语，修饰前面的West African rules, which引导了定语从句，修饰前面的West African rules，定语从句中有插入语though they differed from one tribal group to another，定语从句的动词是involved，宾语是some kind of prohibition。

【亮点回放】此句话的亮点在于采用了分词定语里面套上定语从句，而其中的插入语也是考研英语经典结构，表示补充说明，定语从句的against这个介词短语用得很生动。

【核心词汇】

preference　偏爱

exogamy　外部通婚

derive from　缘起于

West African rule governing marriage　西部非洲制约着婚姻的规定

tribal group　部落群体

prohibition　禁止

unions with close kin　近亲联姻

【参考译文】古特曼表示，这种对于外部通婚的偏爱很有可能缘起于西部非洲制约着婚姻的规定，尽管这些规定在一个和另一个部落群体之间不尽相同，但都涉及到某种对近亲联姻（union with close kin）的禁止。