--Has Tommy finished his project yet?
--Maybe not. He ___on it at lunch time. Let's go to have a look now.
A. has worked B.is working
C.was working D.had worked
--Is that Anna's car?
--It____be hers. She has just gone to the theater for the new opera.
A. can't B.mustn't C.may D.could
Following the traffic rules can help us____ accidents.
A. influence B.repeat C.produce D.avoid
Nowadays Wechat is____used by people for communicating, sharing, chatting, and so on.
A. lastly B.exactly C.widely D.nearly
All the teachers love Mary. She is very in answering teachers' questions in class.
A. polite B.direct C.active D.lively
Those who would like to help others always have more chances to help____．
A. them B.themselves C.us D.ourselves
