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, all involved some kind of prohibition against unions with close kin.

　　參考答案：

　　要點(diǎn)：解釋：本句有兩個(gè)插入語(yǔ)，第一個(gè)插入語(yǔ)Gutman suggests割裂了主句的主語(yǔ)和謂語(yǔ)。West African rules后跟著兩個(gè)修飾成分，第一個(gè)是分詞修飾, 第二個(gè)是以which引導(dǎo)的非限定性定語(yǔ)從句，從句中出現(xiàn)了第二個(gè)插入語(yǔ)though they differed from one tribal group to another，又割裂了從句引導(dǎo)詞與謂語(yǔ)之間的聯(lián)系。

　　譯文：古特曼表示，這種對(duì)于外部通婚的偏愛很有可能緣起于西部非洲制約著婚姻的規(guī)定，盡管這些規(guī)定在一個(gè)和另一個(gè)部落群體之間不盡相同，但都涉及到某種對(duì)近親聯(lián)姻(union with close kin)的禁止