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.