19.He found it hard ____ his class .
A. to catch up with B. to catch up C. catch up with
D. catch up
13.I know the city very well. I ____ there three times.
A. will go B. have been C. went D. have gone
19.He found it hard ____ his class .
A. to catch up with B. to catch up C. catch up with
D. catch up
13.I know the city very well. I ____ there three times.
A. will go B. have been C. went D. have gone