GWD28-Q1省略问题求解

sunyuwei

Scientists claim that the discovery of the first authenticated mammal bones in amber could provide important clues of determining, in addition to how, when mammals colonized the islands of the West Indies.

A. of determining, in addition to how, when mammals colonized the islands of the West Indies.

B. in the determination of how and when the islands of the West Indies were colonized by mammals.

C. to determine how mammals colonized the islands of the West Indies and when they did.

D. for determining when the islands of the West Indies were colonized by mammals and how they were.

E. for determining how and when mammals colonized the islands of the West Indies.

这道题的C选项除了to 的用法有问题，when they did 后面的so 可以省略吗？我认为前面有对应的后面就可以省略，但是解释里面说when they did 后面缺少宾语应该补出，搜了一些帖子也没有很确切的回答~求解

sunyuwei

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