Pollution is a serious problem. Scientists have _______ some good ways to save it.
| A．come up with | B．come on | C．come out | D．come up |
We can’t put off _____ a plan .
| A．make | B．to make | C．making | D．to making |
I saw himwhen I passed by.
| A．ran | B．to run | C．runs | D．running |
Some people plan to ______ a volunteer project to help the disabled children.
| A．put up | B．think up | C．set up | D．cheer up |
You should look after,classmates.
| A．yourselves | B．yourself | C．herself | D．himself |