----Remember to turn off the lights when you leave.---- .
All of us went to the park ______ Bob. He had to look after his sister.
I wonder when they ___ for Beijing. I will go to the train station to see them off whenthey ______.
–--Which would you like, tea or coffee? ---_______. I really don’t mind.
When the students were playing games on the playground, Jim suddenly stopped _____and began to cry, so we stopped _______ what was wrong with him.
–-You should be _______ careful when you take the chemistry exam.---I agree. In this way, I will make _______ mistakes.