用适当的词填空。 1. We shouldn't cut ______ too many trees. 2. I'd like you ______ (come) to supper. 3. Is he good at ______ (run)? 4. My sister usually ______ (wash) her clothes on Sundays. 5. Mr. Zhang ______ (not work) in Beijing. 6. The book isn't easy ______ (read) 7. She ______ (have) an apple now. 8. What size _____ you ______ (need)? 9. ______ (swim) is good for our health. 10. Why not ______ (sing) an English song?