问题
选择题
She has never done anything for them, _______ they have done everything for her.
A．when
B．whereas
C．as
D．because
答案
答案：B
题目分析：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。