Have you ever seen any trees ________ leaves were black because of the polluted air?
| A．whose | B．that |
| C．which | D．who |
He is really considering _____ himself to ______ these children of the poor mountain village.
| A．to devote; educating | B．devoting; educating |
| C．devoting; educate | D．to devote; educate |
Many Americans eat ________ as they actually need every day.
| A．twice as much protein (蛋白质) | B．twice protein as much |
| C．protein as much twice | D．protein as twice much |
I like getting up very early in summer. The morning air is so good _________.
| A．to be breathed | B．to breathe |
| C．breathing | D．being breathed |
After that, he knew he could _________ any emergency by doing what he could to the best of his ability.
| A．get away with | B．get on with |
| C．get through | D．get across |
Hiking is ____ great fun .You will get close to ____ nature and take exercise at the same time.
| A．a; the | B．a; 不填 |
| C．不填；the | D．不填；不填 |