--- Why do you look worried?
-- Fred left the company half an hour ago. His work ____ unfinished since.
A. left B. was left C. has left D. has been left
Professor Li, who I ____ abroad, still teaches in Peking University.
A. think went B. think to have gone C. thought went D. thought had gone
--Why didn’t Tom have his lunch? It’s already one o’clock.
---His pet bird ▁▁ this morning. He▁▁ still for quite a long time in his room crying.
A. died; had sat B. has died; has sat
C. has died; is sitting D. died; has been sitting
I _____ in New York for two years, but I’ve never regretted my final decision to move back to China.
A. was working B. have worked C. worked D. had worked
——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
