He likes to help others ________ he is very busy.
| A．because | B．if | C．even | D．even if |
These years China_______a boom in scientific and technological development.
| A．enjoyed | B．has been enjoying | C．had enjoyed | D．enjoys |
．—Have you finished the work?
—Not yet. I _____ to do it just a moment ago.
| A．set about | B．set up | C．set out | D．set down |
—How often do you go home to see your parents?
—___________, but usually once a week.
| A．As usual | B．No idea | C．It all depends | D．It depends on you |
_____more and more forests destroyed, some animals are facing the danger of dying out.
| A．With | B．By | C．As | D．For |
David’s effort was ______, because he won the first prize in the English speech contest, _____ made his classmates surprised.
| A．paid off; which | B．paid back; it | C．paid for; that | D．paid up; he |