Please do me a favor —_____ my friend Mr. Smith to Youth Theater at 7:30 tonight.
This is the very knife _____ I used to cut apples yesterday.
---- Is it high time that we _____ on the school building? ---- Yes, it _____.
The cost of sales makes up a large part of the prices that _____.
The captain stood by the window, _____ he could see the top of the tower.
That was the only gate _____ we could rush out and save those _____ were in great danger.