Though he was sick,he____swim across the river.

问题描述:

Though he was sick,he____swim across the river.
A.could B.was able to C.can D.such like

B
C时态不对
D语法不对
A里could用在过去时里通常想说能做但没做的事.比如与could have连用
B是陈述事实 表明他游过去了