用括号内所给动词的适当形式填空
1. You mustn't come into the room if you ( not invite) .
2. Tom always goes to her Math teacher for help when something (worry) him.
3. Look! The river _______________(rise) two feet because of the heavy rain.
4. In the old days the working people in our country ____________ (look) down on.
5. Which dirty blanket ____________ (wash) first is not decided yet.
6. The doctor helped the man by _______________(operate)on him.
7. Why can't you just believe me? I ______________ (tell) you everything I know!
8. —Do you still remember that we first met in the library one year ago?
—Of course. You (read) a comic book then.
