问题

_______ caused the accident is still a completemystery.

A:What
B:That
C:How
D:Where

正确答案是：

同类题型

Thank you very much for___________ your birthday party.

The door opened and in ______ .

We believe the time and hard work _______ in completing such an important project are worthwhile.

Would you mind ___________ more slowly ，I can’t follow you.

Rabbits will run away quickly if there is _______.