______ regular exercise is very important, it is never a good idea to exercise too close to bedtime..
A．If B．As C．Unless D．Although
No matter how bright a talker you are, there are times when it is better ______ silent.
A．remain B．be remaining
C．to remain D．having remained
There is ______ in our office that when it is somebody’s birthday, they bring in a cake for us all to share.
A．balance B．tradition C．concern D．relationship
Mr. Smith ______ a grammar book meant for senior high school students and will almost finish it.
A．has been writing B．has written
C．was writing D．has been written
—I’m just going to finish the work off first.
—Go on if you _______.
A．can B．may C．must D．shall
The new stadium being built for the next Asian Games will be ______ the present one.
A．three times as big as B．as three times big as
C．as big as three times D．as big three times as
