21. Kathy ______ a lot of Japanese while working with some Japanese engineer.
A. made up B. took up C. pick up D. turned up
22. As Polly observed the passengers on the train, she _______that she was being watched by a tall man in a dark coat.
A. feared B. sensed C. sighted D. sniffed
23. By the time she reached the corner of the street, the footsteps _________.
A. had gone B. were gone C. are missing D. have disappeared
24. It is often that human beings are naturally equipped to speak.
A. said B. to say C. saying D. being said
