—Mum, I'm tired.
—Well, if you ________ go to bed after midnight every night, what do you expect?
A．will B．may
C．should D．can
Brain, like muscles, also needs some kind of exercise and nutrition. The more you use your brain in the right direction, the more you ________ enhance your ability.
A．could B．might
C．shall D．will
We all know that we ________ our carbon footprint, but I suspect that many people wouldn't be prepared to go as far as Joan Pick, a retired scientist living in south London.
A．must have reduced B．should have reduced
C．may have reduced D．could have reduced
No matter how healthy you ________ be, you need to consult a doctor from time to time.
A．should B．will
C．must D．may
—May I smoke here?
—If you ________， choose a seat in the smoking section.
A．should B．could
C．must D．may
We can't use it to tie the goods because it ________ be broken at the weakest position.
A．shall B．may
C．can D．would
