Question

The teacher didn't know ________ broke the window.

1. A.
   which
2. B.
   whose
3. C.
   whom
4. D.
   who

Answer 1

D
本題中賓語(yǔ)從句中缺少主語(yǔ)，需要指出“誰(shuí)”這個(gè)動(dòng)作的執(zhí)行者。