用所给词的适当形式填空。 1. It's very nice of you _____ (invite) me to the party. 2. It's cold outside. You'd better _____ (not take) off your coat. 3. He was pleased _____ (receive) the present. 4. How many _____ (act)in this play all together? 5. At last we decided _____ (set) off at once. 6. What we have to do first is _____ (find) a solution. 7. Let me _____ (do) it for you. 8. We must try _____ (live) together happily. 9. _____ you _____ (impress) by the play? 10. I think it's hard _____ (get) to the top of the high Mountain.