With ______ successful launching of Tiangong-1, China’s space dream has taken ______ step closer to reality.
Mr. Smith couldn’t open the door because his naughty boy _______ it from the inside
I know little about the accident because not much_________ about it up to now
I’ve been away for only three years, _____ I can hardly recognize my hometown
In China, you _____ vote when you are 18.
The professor could hardly find sufficient grounds _____his arguments in favor of the new theory.