说明
wh-疑问词 + to-v 作宾语
核心问题
（1）There isn't any difference between the two. I really don't know ____.
A. where to choose B. which to choose
C. to choose what D. to choose which(全国高考)
(2) I've worked with children before, so I know what ____ in my new job.
A. expected B. to expect C. to be expecting D. expects(全国高考,00-19)
如何分析上句中的 which to choose 和 what to expect?
词典解答
见 infinitive ，expect ，when 。