I should not have laughed if I________you were serious. (2013·江苏,30)
It was when she was sleeping in her bedroom __________ a thief broke into the house.
________ take the aeroplane all the way, they decided to fly to Vancouver and then take the train from west to east across Canada.
It’s heavy, but I can ________ to carry it upstairs.
---- It is a long time since I saw my sister. ----________ her this weekend? Why not to visit B. Why not visit C. Why not visiting D. Why don’t visit
What _______ the foreign experts most is that the new factory is perfectly environment-friendly.