＿＿＿＿＿ it rain tomorrow we would have to put off the visit to the Yangpu Bridge. A. WereB.

问题补充：

＿＿＿＿＿ 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：

A. Were

(答案→)B. Should

C. Would

D. Will

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。