09届高三英语第一学期期中考试
第二部分:知识运用(共两节,满分50分)
第一节 单项选择(共20 小题;每小题1分,满分20分)
21.A good idea occurred to Mr Baker ______to his invention recently.
A.while applying B.while applied
C.while he was applying himself D. while applying himself