38.　 Liu Tao needs some pencils. (改为否定句)

37.　 It is hot in summer in New York. (对画线部分提问)

36.　 The boy can jump higher than the girl. (改为否定句)

35.　 Helen is good at singing. (同义句)

34.　 I see a man behind me. (改为一般过去时)

33.　 Tom jumps as far as Mike. (改为否定句)

32.　 Wang Bing is heavier than Gao Shan. (对画线部分提问)

31.　 He did his homework in the classroom. (改为否定句)

30.　 David and Mike are going to planting trees this afternoon. (对画线部分提问)

29.　 Liu Tao is watering flowers in the garden. (对画线部分提问)