The traffic slowed down because of the heavy snow in Yushu County, presenting a new _____ to the discovery from the earthquake.
| A．suffering | B．disaster | C．damage | D．challenge |
Americans eat _______ vegetables each person today as they did 20 years ago..
| A．twice as many | B．many as twice | C．as many twice | D．as twice many |
— Would you allow me ________ here?
— Sorry. We don’t permit _________ in the lab.
| A．smoking; smoking | B．to smoke; to smoke | C．smoking; to smoke | D．to smoke; smoking |
— Do you know where David is? I couldn’t find him anywhere.
— Well. He ________ have gone far — his coat is still here.
| A．shouldn’t | B．mustn’t | C．can’t | D．wouldn’t |
Sara hopes to become a friend of _________ shares her interests.
| A．anyone | B．no matter who | C．whoever | D．whomever |
He has some doubt ________ he will succeed in his research work.
| A．whether | B．weather | C．which | D．that |