_______ apple four hundred years ago led to the law of gravity while _______ apple designed by Steve Jobs has changed our life greatly.
| A．The; an | B．An; an |
| C．An; the | D．The; 不填 |
The traffic slowed down because of the heavy snow in Yushu county, presenting a new _________ to the recovery from the earthquake.
| A．suffering | B．disaster | C．challenge | D．damage |
—The terrible accident is under investigation.
—Actually, quicker action _________ those workers trapped in the mine.
| A．might have saved | B．must have saved | C．should have saved | D．could have saved |
“The Secret Life of Emily Dickinson” _________ U.S. bookstores this week and soon became a best seller.
| A．hit | B． appeared |
C．moved | D．touched |
I’m terribly sorry to turn you down this time, but I promise I will _________ to you next time.
| A．pick it up | B．make it up | C．turn it up | D．set it up |
The government has taken some measures to solve the shortage of electricity, but it may be some time _________ the situation improves.
| A．since | B．when | C．unless | D．before |