问题：
If you don"t want to fall behind others, you must _____ current events.
[ ]
A. keep track of
B. keep track
C. keep touch with
D. keep in touch
If you don"t want to fall behind others, you must _____ current events.
B. keep track
C. keep touch with
D. keep in touch
[ ]
A. keep track of B. keep track
C. keep touch with
D. keep in touch
参考答案：