---May I go out to play with my friends now, Dad?
---No. You ______ let your mother know first.
A. may B. need C. must
I really don’t know _______
| A．how to do | B．what to do it |
| C．how to do it | D．which to do it |
Students are often told _____ at people who are in trouble.
| A．not to smile | B．to smile |
| C．not to laugh | D．to laugh |
It is dangerous _______ football on the road.
| A．for us to play | B．of us playing |
| C．for us playing | D．of us to play |
He was ______ go any further.
| A．too tired to | B．tired enough to |
| C．so tired that | D．tired so that |
I need to get up early, please _______ tomorrow morning.
| A．wake I up | B．woke me up |
| C．woke I up | D．wake me up |