Hard as he worked，________he couldn’t make enough money to support his family.
A、and
B、but
C、therefore
D、不填
【正确答案】：D
【题目解析】：选D.前面的从句是个特殊的由as引导的让步状语从句,原来语序是as he worked hard.这个as就相当于although但是它有特殊用法.即它引导的让步状语从句需要倒装要把形容词提前,在本题中即把hard提前，as就是引导，词因此不用再加连词了。
