请问这几句用what引导的从句有无问题,有错误地方请帮忙修改一下,还是要用what引导从句,

题目

请问这几句用what引导的从句有无问题,有错误地方请帮忙修改一下,还是要用what引导从句,
1 Could you show me what you writed?
2 This is what we should keep in mind
3 We must not put off in tororrow What we can do today.
4 What they saw in china made a deep impression on them.

答案

1 Could you show me what you wrote?2 This is what we should keep in mind3 We must not put off what we can do today to tororrow .4 What they saw in China made a deep impression on them.