用所给词的适当形式填空，每空不限一词。 1. I think it's _____ (use) to talk with him. It's difficult to change his mind. 2. The terrible snowstorm kept them from _____ (ski) last week. 3. My uncle will come back from London. I'm waiting for his _____ (arrive). 4. _____ (wolf) eat smaller animals when they are hungry. 5. _____ (luck), he was hurt badly. 6. His grandpa was lucky enough to stay _____ (live) during the earthquake. 7. Lushan is so beautiful that he wants to go there for the _____ (two) time. 8. We should encourage people _____ (not cut) trees any more. 9. I _____ ( drive ) to Beijing when my car broke down. 10. The young trees _____ (die) soon if you don't water them in time.