But for their generous help, the experiment______completed so quickly.A、shouldn’

游客2024-08-22  13

问题 But for their generous help, the experiment______completed so quickly.

选项 A、shouldn’t be
B、couldn’t have been
C、wasn’t
D、hadn’t

答案 B

解析 句意:要不是他们慷慨相助,试验不可能这么快完成。but for要不是…,位于句首句子用虚拟语气。couldn’t have been本不可能实现但却实现了,虚拟语气。
转载请注明原文地址:https://tihaiku.com/zcyy/3730601.html
最新回复(0)