几道非谓语的，急！

1.see sth done/do,无see sth to be done
2.seeing 表主动，sb's frightened,sth's frightening
3.动宾短语做主语，而且是主动，用ing形式
4.固定用法 considering(that)..../seeing that....
providing that...../judging from.....
5.be close to doing,to为介词。如：look forward
to doing/stick
to doing等
6.固定用法 so... as to 如此的。。来。。
7.注意：worthwhile+to do
worth someone's while + 动名词，这里while是名词做worth的宾语，词组意为“有好处”“值得某人去做”
8.prevent...(from)doing.... 注意为主动
如keep...from doing../protect...（from）都为防止的意思