Playing with a cell phone, he suddenly ________ the teacher staring at him.
A. knew of B. became aware of
C. reflected D. aware for
She seemed ________ the book before, but she said she had never.
A. to read B. to have read C. to be reading D. reading
________ on the subject for half an hour, Liu Ying suddenly stopped.
A. To be worked B. To work
C. Having worked D. Having been worked
She offered me practical ________ with my research, for which I would appreciate for my whole life.
A. conduct B. certificate C. admiration D. assistance
“ Look at him! He behaved ________ nothing had happened”, said Mary.
A. as if B. even if C. if D. unless
They were singing and dancing to ________ their high spirits though it was very cold.
A. keep up B. build up C. bring up D. pick up
