Most environmental problems exist because adequate measures for preventing them ____in the past.
| A．not being taken | B．didn’t take |
| C．were not taken | D．haven’t taken |
Much time _____ sitting at a desk, office workers are generally troubled by health problems.
| A．being spent | B．having spent |
| C．spent | D．spending |
-Jim, can you work this Sunday?
-? I've been working for two weeks on end.
| A． | Why me | B． | Why not |
| C． | What if | D． | So what |
Schools should be lively places where individuals are encouraged to _____ to their greatest potential.
| A．accelerate | B．improve |
| C．perform | D．develop |
The number of smokers,（） is reported, has dropped by 17 percent in just one year.
| A． | it | B． | which | C． | what | D． | as |
—Go and say sorry to your Mom, Dave.
—I’d like to, but I’m afraid she won’t be happy with my ______ .
| A．requests | B．excuses |
| C．apologies | D．regrets |