you make a plan，you,d better_____the advantagesand disadvantages of it

_____ we have built “the Green Wall’, _____we still need to work hard to protect our environment.

Did you find the notebook ______ Jim hadgiven me for my birthday

Had you taken the doctor’ s advice yesterday, you _____ all right now.[ ]

“When did he leave the classroom” “He left_______ you turned back to write on the blackboard”