--- Could you tell me what he said just now?
--- Sorry, I ______ what was going on outside.
| A．had thought | B．was thinking | C．thought | D．think |
Mr Black has two sons, one of ________working as a doctor.
| A．them | B．who | C．whom | D．whose |
—Who is the man ______ by a group of students there?
—A professor _____ research on physics.
| A．followed; did | B．following; did |
| C．followed; doing | D．following; doing |
— You were late again, Peter.
—Sorry, I ______ to be here on time, but the traffic on the roads _____ heavy.
| A．wanted; was | B．had wanted; was |
| C．wanted; would have been | D．had wanted; would have been |
_____, I believe, and you will find Tom is very outgoing．
| A．Having a talk with the student | B．Given a talk with the student |
| C．If you have a talk with the student | D．One talk with the student |
from the top of the tower ,the south foot of the mountain is a sea of trees.
| A．Seen | B．Seeing | C．Having seen | D．To see |