Compared with 2 million tons last year, our coal output has increased _____three times; that is to say, our coal output has increased_____8 million tonsthis year.
They are of _______ height, but I think Mary_______ the job.
Every day we students are expected to _______ at least an hour _______ English.
After the long journey, the three of them went back home,___________.
There is some doubt _______ we can get the first place in the competition.
Don’t forget to insure against theft ______ you have things ________ .