She has never done anything for them they have done everything for her.A. whenB. whereas

问题补充：

She has never done anything for them, they have done everything for her.

A. when

B. whereas

C. as

D. because

答案：

A. when

(答案→)B. whereas

C. as

D. because

解析：句意：她从来没有为他们做过任何事，而他们为她做任何事。A. when当…时候，B. whereas然而，C. as因为，正如，D. because因为，所以选B。