Only after the woman had her own child, _____ how difficult it was to be a mother.
The notice ______ “No smoking”. A is told B reads C tells D is read
The doorbell had been ringing for several minutes before it ______. A answered B had answered C was answering D was answered
The box _____. Better call in a mechanic(修理工). A isn’t open B hasn’t been open C isn’t be open D won’t open
The workers _____busily when the boss came to look for something she ______in the office. A had worked, had left B were working ; had left C working ; had left D had worked; left
I’m afraid it will be two months______.A when I come back B when I’ll come back C before I come back D before I’ll come back