—Your grandparents like travelling, right?
—Yes. They think one is never ________ enjoy life.
| A．too young to | B．young enough to |
| C．old enough to | D．too old to |
--- Are you worried when your son often plays computer games?
--- Yes. I think playing too many computer games ______ on teenagers.
| A．have a good effect | B．has a good effect |
| C．has a bad effect | D．have a bad effect |
I won’t watch TV ______ I finish my homework.
| A．while | B．after | C．until | D．as |
---______ to give the letter to Mr. Wang. It’s very important.
---No, I won’t.
| A．Remember | B．Don’t forget | C．Be sure | D．Make sure |
On the 40th Earth Day, Dr Wang gave us a talk on the importance of ______ the earth.
| A．practicing | B．preventing | C．polluting | D．protecting |
---What did the policeman say to you just now?
--- He asked _______ when the accident happened.
| A．what I was doing | B．what was I doing | C．what I am doing | D．what am I doing |