Asateacher,youshouldnot_______thestudentsfromaskingquestionsinclass.
A、ruinHeworksinouruniversityasavisiting_______,notasaformalfacultymember.
ProfessorSmithisalsothe_______oftheinternationalprogramoffice.Ifyouhaveanyproblemwhenyoustudyhere,youmaygotohimforhelp.
Whenmakingmoderncameras,peoplebeganto_______plasticsformetal.
Thismorningintheclass,ourteacherlosthis______atlastbecausehecouldnotstandanymore.
ThecollegestudentsinChinaare_______fromsmokingoncampusbecausethiswilldothemnogood.
