The bicycle riders___weasr helmets.a.haven't to b.mustn't c.

The bicycle riders___weasr helmets.a.haven't to b.mustn't c. mustn't mustn't to haven't to don't haven't to They must have finished the work,---?A,mustn't they B,haven' You mustn't play________match A:at B:with C:to A. to; still haven’t B. to; haven’t still C. with; still hav You _____do that,if you don't want to.a.mustn't b.needn't c. you________ do it even if don't want to A.can't B.mustn't C. you must clean the classroom,you?a.needn’t b.mustn’t c.can’t That must have cost you much money,___it?A.mustn't B.haven't Please be quiet!The other ( ) hear very!A.can't B.mustn't C. you ____ play games in the busy street A mustn't B needn't C you ___ (A shouldn't B mustn't C needn't D can't)eat the sou