问题
选择题
If it ______ tomorrow, our picnic _______ to be put off.
A．rains;wouldhave
B．shouldrain;wouldhave
C．rains;has
D．wouldrain;wouldhave
答案
答案：B
此题考查的是if条件从句与将来事实相反的虚拟语气，条件句使用主语+should +do或+did/were或were to do 三种形式，主句使用could/might/would +do。因此选B。