Thisriverformsanatural_______betweenChinaandKorea.
A、boundaryWhenyoufillintheapplicationform,pleaseuseyour_______addresssothatwecancontactyoueasilylater.
The college students in China are _______ from smoking on campus because this will do them no good.
Weare_______attherapidprogressMarkhasmadeinthissemester.
Carelessnessmadehimfallinhisjob_______.
Wecannottrusthimanymorebecauseheoften________hisduty.