问题补充:
When they went into the park, they saw someone Chinese Kongfu.
A. plays
B. played
C. to play
D. playing
答案:
A. plays
B. played
C. to play
(答案→)D. playing
解析:考查感官动词see的用法。句意“当他们走进公园时,他们看到有人在打中国功夫。”,“看到某人正在做......”用see sb. doing sth.,“看到某人做了某事”用see sb. do sth.。根据句意,用playing,故选D。