This task is really beyond me．
Well， if you _________solve it， you won't get paid．（ ）
A．can'tB．needn'tC．mustn'tD．shouldn't
Didn't you see the zebra crossing？ You __________ slow down， son!
Sorry， sir． Am I going to fail the test？（ ）
A．can'tB．canC．mustn'tD．must
It's not __________ to be friendly． You have to be a friend． Go and talk to Sam．（ ）
A．good enoughB．late enough
C．too goodD．too late
He stayed up very late that night． __________ he woke up in the morning， the sun was already high up in the sky．（ ）
A．UntilB．AfterC．WhileD．As
It's said that drinking coffee __________ cancer． Do I have to give it up？
Relax! Not everything on Wechat is true． In fact， a coffee a day keeps the doctor away．（ ）
A．causesB．has causedC．causedD．had caused
You're the future of this country． Don't keep asking what this country can do for you． Ask_________ what you can do for this country．（ ）
A．usB．ourselvesC．youD．yourselves