Freemedicalserviceis_______tonearlyallthecollegestudentsinChina.
Asateacher,youshouldnot_______thestudentsfromaskingquestionsinclass.
Thisriverissobigthatitisimpossibletobuilda_______underitwithoutmoderntechnology.
ProfessorSmithisalsothe_______oftheinternationalprogramoffice.Ifyouhaveanyproblemwhenyoustudyhere,youmaygotohimforhelp.