Whenmakingmoderncameras,peoplebeganto_______plasticsformetal.
A、surroundThe_______isnearlydead,soIcannotstartthecaragain.
Asateacher,youshouldnot_______thestudentsfromaskingquestionsinclass.
Pine trees are usually believed to _______ cold weather.
In the United States, the foreign policy is decided by the ________ government, not by each state.
Professor Smith is also the _______ of the international program office. If you have any problem when you study here,you may go to him for help.
