10.，wewouldhavetoputoffthevisittothehistorymuseum(rain)如果明天下雨，我们将不得不推迟去历史博物馆参观。

Question

10.         ，we would have to put off the visit to the history museum  (rain)

如果明天下雨，我们将不得不推迟去历史博物馆参观。

Answer 1

10. Should it rain tomorrow/If it should rain tomorrow/Were it to rain tomorrow从下文动词用的是would have to而不是will have to 可知，空白处应用虚拟的条件。