GWD 2-3 求助

memory1230

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

1. is expected to make an offer to buy First Interstate Bank until a merge agreement is signed that includes a provision for penalties if the deal were
2. is expected to make an offer for buying First Interstate Bank until they sign a merge agreement including a provision for penalties if the deal was
3. is expected to make an offer to buy First Interstate Bank until a merge agreement be signed by them with a provision for penalties if the deal were
4. are expected to make an offer for buying First Interstate Bank until it signs a merge agreement with a provision for penalties included if the deal was
5. are expected to be making an offer to buy First Interstate Bank until they sign a merge agreement including a provision for penalties if the deal were

答案是c，c里面为什么用“be signed by” be动词原形？ 不懂。 还有最后“if the deal were” 为什么用were? 不是was? deal不是单数吗？

天蝎座1107

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