We wouldn't lose heart even if we _____again.

We wouldn't lose heart even if we _____again.
A、would fail
B、failed
C、had failed
D、fail
【正确答案】：B
【题目解析】：考查虚拟语气。句意：即使我们再次失败，也不会丧失信心。主句用“would＋动词原形”，从句用一般过去式。