At last he finish the work ahead of time. A.could B.was able to C.could have don
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At last he finish the work ahead of time.
A.could B.was able to
C.could have done D. would have been able to
试题答案
B
解析:
此句检测对can和be able to辨析使用的能力。从时态上讲,can只有过去,而be able to可用于各种时态;从语意上讲,be able to的过去可表示“设法完成某事”,相当于managed to do sth.而could则无此?用法。?