Ⅰ.单句语法填空
1．If the weather________(be)better，we could have had a picnic.But it________(rain)all day.
2．Had it not been for the free ticket，I________(not go)to see the film.
3．What ________(happen)had Bob walked farther，as far as the river bank?
4．________he come，the problem would be settled.
