(2017·北京) Jim has retired, but he still remembers the happy time ________ with his students.
A. to spend B. spend
C. spending D. spent
To begin with, I was____of his promise, but I was soon convinced by his practical actions.
A. calm B. fierce C. sceptical D. patient
In the dark I could see a man lying on the floor, ____up with rope, which was____.
A. tied; terrified B. tied; terrifying
C. was tied; terrified D. was tied; terrifying
Recent research has____the natural mystery, which has amazed the world.
A. got a kick out of B. got stuck in
C. thrown light on D. made sense of
（2017·江苏卷·单项填空） He hurried home, never once looking back to see if he ____________.
A. was being followed B. was following
C. had been followed D. followed
I bought my mother a present and wished to give her a surprise on her birthday, but my father____the secret.
A. put away B. put off C. gave away D. gave off
