This river forms a natural _______ between China and Korea.
A、boundaryA
暂无解析
Ifyouhaveanyproblemsduringyourstudyhere,pleasedonot_______tocallmeforhelp
ProfessorSmithisalsothe_______oftheinternationalprogramoffice.Ifyouhaveanyproblemwhenyoustudyhere,youmaygotohimforhelp.
Carelessnessmadehimfallinhisjob_______.
Whenmakingmoderncameras,peoplebeganto_______plasticsformetal.
Thisriverissobigthatitisimpossibletobuilda_______underitwithoutmoderntechnology.
