So far, the moon is the only one of the heavenly bodies in space ______ reached by manned spaceships.

I hear the plane of MH370 has been found!—Really？I wonder if some people are still alive.

The chairman thought __________ necessary to invite Dr. Smith to speak at the meeting.

Thanks_____ your help, and now I have made great progress in my English. [ ]

Which coat would you like?—I’d like _________ orange one with white flowers on it.