______ a person looks like is not as important as ______ he or she grows up to be.

.—I can’t find Mr. Smith.  Where did you last see him this morning?—It was in the hotel _______ he stayed.    

It’s quite a time _____ Liu Xiang was injured in the foot, but we are sure it won’t be long _____ he returns to the track.

I would appreciate _______ you could give me some advice on TOFEL test.

Researchers have found clear and convincing evidence ________ happiness isthe key to better health and longer lives.