过去完成时when 、before、after造句每个一句,要翻译,

问题描述:

过去完成时when 、before、after造句每个一句,要翻译,

句型一:过去完成时+when+一般过去时 如:
I had finished my homework when Mum came back.妈妈回来的时候,我已经完成我的作业了.
句型二:过去完成时+before+一般过去时 如:
I had finished my homework before Mum came back.妈妈回来之前,我已经完成我的作业了.
句型三:after+过去完成时+一般过去时 如:
After I had finished my homework,Mum came back.我已经完成我的作业之后,妈妈才回来.