问题
选择题
--- The accident might not have happened , had we been more careful .
--- But we _______.
A．didn’t
B．hadn’t
C．weren’t
D．don’t
答案
答案：C
如果我们再小心一些的话事故也许不会发生。根据所给语境might not have happened可知是对过去情况的假设所以知道答语叙述的是过去的事情故选C