21. After doing _____ series of exercises, he finally passed _____ driving test.
A. /£»the          B. a£»the          C. the£»a         D. /£»a
22. Many Chinese students speak English with a strong Chinese _____, but foreigners can understand what they say.
A. noise           B. voice            C. accent        D. sound
23. I’m new here. Could you tell me _____, please?
A. when the first bus arrives         B. when will the first bus arrive
C. when did the first bus arrive     D. when does the first bus arrive
24. May I have your attention, ladies and gentlemen? The plane _____ in fifteen minutes. Please power off your cell phones.
A. was taking off   B. is taking off      C. has taken off    D. took off