_____ scores of times, but he still couldn’t understand it.
A. Having explained B. Having been explained
C. Though it was explained D. It was explained
--- He was nearly killed by a car once.
--- Oh. when was________ exactly?
--- It was in 2002 __________ he was riding a bike on the drive-way.
A. this; that B. that; when C. that; that D. this; when
The students expect there ______ more reviewing classes before the final exam.
A. is B. to be C. being D. have been
______ the secret of nature, the young scientist has little time for entertainment．
A. Devoted to research B. Devoted himself to research
C. Devoted to researching D. Devoting to research
_________ into a famous university made his parents very happy.
A. Tom was admitted B. Tom be admitted
C. If Tom was admitted D. Tom’s being admitted
________the working efficiency, the boss allows the employees to have a coffee break.
A. Improving B. To improve C. Having improved D. Improved
