Question

John failed in the driving test，________he had prepared a lot for it before.

A．as                                                   B．when

C．once                                                D．though

Answer 1

答案：　D

解析：　本题考查连词的用法。句意为：尽管之前约翰为驾驶测试做了许多准备，但他还是没有及格。as引导让步状语从句时，从句应部分倒装，可排除A项；B、C两项都不引导让步状语从句。