The painter mostly ________ realistic painting methods, but also used some folk and traditional Chinese painting techniques.

uld have gone fishing yesterday,butit ______all day.

30·You can make a complaint to the local government____ you are happy with the way things are

During the mourning period（悼念期）flags are __________at half-mast, all public amusement will be stopped.

Psychologists are also________ that both language and learning are in some sense social phenomena. [ ]