Entering the room, I found Mary ______at the desk and ______a letter.
A. Seated；wrote B. Sitting；written
C. Seating；writing D. Seated；writing
_________on the main street, the market was busy yesterday.
A. Located B. locating C. being located D. to be located
They were surprised that a child should work out the problem _____ they themselves couldn’t.
A. when B. where C. until D. while
--- You must obey every word of mine.
--- _____ I don’t?
A. What if B. So what C. How if D. Only if
_____ the lecturer more clearly, I arrived early and chose a front seat.
A. Hear B. To hear C. Heard D. Hearing
---You have made great progress in your English study, haven’t you?
--- Yes, but much _____ .
A. remains to do
B. is remained to do
C. remains to be done
D. is remained to be done
