新prep-217，有个地方不明白，请指教

蔻华施

217.

 

Not one of the potential investors is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were not to be concluded.

A. is expected to make an offer to buy First Interstate Bank until a merger agreement is signed that includes a provision for penalties if the deal were

B. is expected to make an offer for buying First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal wasx

C. is expected to make an offer to buy First Interstate Bank until a merger agreement be signed by them with a provision for penalties if the deal werex

D. are expected to make an offer for buying First Interstate Bank until it signs a merger agreement with a provision for penalties included if the deal was

E. are expected to be making an offer to buy First Interstate Bank until they sign a merger agreement including a provision for penalties if the deal werex

 

正确答案是选A，我之前是选择的D，因为我直接看最后一个deal后面的系动词，发现A肯定是不正确的，deal 后面怎么接的were呢？哪位NN帮我解释下？

xuhuixin

if虚拟语气中只能用WERE，不能用WAS，不论是不是三单。

蔻华施

谢谢亲爱滴MM....明了！