1/ +They weren`t in Rio last summer.

     +Were they in Rio last summer?

2/  +We didn`t do our exercises this morning.

      +Did we do our exercises this morning. ( hoặc là nếu các này sai thì Did you do your exercises this morning? )

3/   +My parents didn`t come to visit me last July.

       +Did your ( my ) parents come to visit me ( you ) last July?

4/    +The hotel wasn`t very expensive.

        +Was the hotel expensive?

5/     +I didn`t have a bicycle when I was young.

         +Did you ( I ) have a bicycle when you ( I ) were ( was ) young?

6/      +The children didn`t go to the zoo yesterday.

          +Did the children go to the zoo yesterday?

7/       +Ernie didn`t eat the last donut.

           +Did Ernie eat the last donut?

-Chúc bạn học tốt! Mấy cái mình bỏ trong ngoặc thì bạn dùng khi mà câu mình khi không ngoặc là sai nha ! :)