—Have you cleaned the room yet? —Yes,I _______it an hour ago. A.clean B.has cleand C.cleaned
You will realize what I have done for you _____.
As teenagers, we should study hard _____surf the Internet all day.
Please _____ your homework _____ before you hand it in.
An online magazine makes us ______ more paper.
Mum bought me a dress _____ the visit to Hainan Island.