They _ the train until it disappeared in the distance.
When are you going to Hainan? — I am going there _____ June 8, 2007. [ ]
Some students often drop litter carelessly in our school. What can we do?- We can _______ some signs to remind them not to do that again.
You can’t imagine what great difficulty I had _______ my father to agree to my plan for the holiday.
__________ will the meeting last? –Less than an hour.