We would have called a taxi yesterday if Harold us a ride home.
A. didn’t offer
B. wouldn’t offer
C. hasn’t offered
D. hadn’t offered
网友回答
A. didn’t offer
B. wouldn’t offer
C. hasn’t offered
(答案→)D. hadn’t offered
解析：句意：如果哈罗德昨天没有送我们回家的话，我们将叫一个出租车。从主句的谓语动词would have called可以看出这是对过去的虚拟，那么从句应该用had+done，故选D。