It’s quite normal to___ ten percent of the cost of a building for a period of six months or so, in case faults are found in it.
Mr. White told us _______ run up and down the hall.
Only when I left my parents for Italy _____ how much I loved them.
He is the man _________ you can turn when you are in trouble.
Look at the timetable (时刻表). Hurry up! Flight 4026 _______ off at 18:20.
Do you have any difficulty ______ these flowers? I’d like to help you if you need.