完形填空。 Mr Smith is a good teacher. He is 1 America. He teaches English. He is very friendly to 2 students. There 3 fifty students in his 4 . It is a big class. There are twenty-nine 5 in his class. The others are boys. Mr Smith and his students are good 6 , too. Now the school is over. Some of the students are 7 football on the playground (操场). Jane and Mary are cleaning the classroom. Two tall 8 are flying a kite over there. Mr Smith is playing with the 9 on the playground All of them 10 playing very happily. (     )1. A. from (     )2. A. he (     )3. A. am (     )4. A. school (     )5. A. boys (     )6. A. friend (     )7. A. play (     )8. A. girl (     )9. A. boys (     )10. A. am B. to B. him B. is B. grade B. girls B. teachers B. plays B. child B. girls B. is C. in C. his C. are C. class C. children C. students C. to play C. boys C. child C. are D. at D. its D. to be D. group D. child D. friends D. playing D. parent D. children D. to be