The old couple looked at the plane with their son on it until it was ______.
| A．at the first sight | B．out of sight |
| C．in sight | D．at the sight of |
We should prevent pollution ______ happily.
| A．from living | B．to live | C．from being lived | D．to living |
.It is sleeping late in the morning that ______ being late for work.
| A．devotes to | B．sticks to | C．sees to | D．leads to |
______ such heavy pollution already, it may now be too late to clean up the river.
| A．Having suffered | B．Suffering | C．To suffer | D．Suffered |
As we joined the big crowd I got ______ from my friends.
| A．separated | B．spared | C．lost | D．missed |
—Did you see a man in black pass by just now?
—No, sir. I ________ a newspaper.
| A．read | B．was reading | C．would read | D． am reading |