——Did you see Grace in the teacher’s office？
——Yes, she ______to him why she didn’t hand in her assignments
A. is explaining B. was explaining C. had explained D. explained
----I’ve got to go now.
---Must you? I you could stay for dinner with us.
A. think B. thought C. have thought D. am thinking
She stared at the painting, wondering where she it.
A. saw B. has seen C. sees D. had seen
—What do you think of the movie?
—It’s fantastic. The only pity is that I the beginning of it.
A. missed B. had missed C. miss D. would miss
Over the past decades, sea ice in the Arctic as a result of global warming.
A. had decreased B. decreased C. has been decreasing D. is decreasing
During the period of recent terrorist activities, people _______ not to touch any unattended bag.
A. had always been warned B. were always being warned
C. are always warning D. always warned
