—What ______ when the earthquake happened on May 12th ?—Er, I was having a geography class in the classroom. A. are you doing B. did you do C. were you doing D will you do
---Why don’t we go to the new Sichuan restaurant for a meal? -----_____
-----_____ leave at the end of this month. -------I don’t think you should do that until _____ another job.
He tried his best to solve the problem, _____ difficult it was.
The missing boy was last seen_____ near the East Lake.
Out of ___ for the homeless children he gave them shelter for the night.