___________ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.

___________ it rain tomorrow, we would have to put off the visit to the Yangpu Bridge.

A.Were

B.Should

C.Would

D.Will

答案及解析： B

解析：

含有if的虚拟条件句可把if省略，而把had，should，were等提到句首，构成倒装。