从题中所给的A、B、C、D四个选项中，选出可以填入空格的最佳选项。
1. The film star wore dark glasses so that no one would ___________ him.
A. know B. reach C. recognize D. realize
2. You have no idea how she finished the relay race ________ her foot wounded so much.
A. for B. when C. while D. with
3. Mrs Smith warned her daughter _________after drinking.
A. never to drive B. to never drive C. never drinking D. never drive
4. －Why did you talk to the teacher after class?
－I didn’t understand______________ during the lecture.
A. the problem did she tell us B. how did she say
