people must_____(follow) the rulestwice用社么提问是how long吗

问题描述:

people must_____(follow) the rules
twice用社么提问
是how long吗

答案是follow~~
must后+上动词的原型~~无论是什么时态,因为must是情态动词~~

follow
must+动词原型
意思是人们要遵守法则
错,twice是次数要用how often提问