未知题型 ______ one time, Manchester was the home of the most productive cotton mills in the world.A) On B) ByC) At D) Of

未知题型 If only the committee _________ the regulations and put them into effect as soon as possible.A) approve B) will approveC) can approve D) would approve

未知题型 You see the lightning _________ it happens, but you hear the thunder later.A) the instant B) for an instantC) on the instant D) in an instant