【巩固练习】 . 选用can, may, must, cant, mustnt, could填空。1. There is air around us, but we _ see it.2. You _ play football in the busy street.3. It _ be Mr. Brown. He has gone to America.4. Tom _ come to my birthday party, but Im not sure.5. _ you please give me some water ?6. Must I finish reading the book today? Yes, you _. No, you _.7. May I take this magazine out of the reading-room?No, you _. 8. I_ swim,
