fasten one's attention 后用什么介词是否只跟on/upon

fasten one's attention 后用什么介词是否只跟on/upon 【求详解】一道托业语法选择题：It's mandatory that passengers ( ) their seat belts.A.fasten B. fastening C.should fasten D. have fastened fasten啥意思 fasten的词根是什么? fasten your seatbelt是什么意思 tech fasten是什么意思 one,ones,one’s one's one's What's one's What's one plus one what's one and one one one's way to ones one one's ones' what's one and one? What's one and one? ones one one's ones' What's one and one