youmustdimdyourhighlightsevrysuddenlyifthereisaoncomingcarofapoliceyoumustbedimdyourhighlightsevrysuddenlyifthereisaoncomingcarofapoliceyoumustbepreparedforworkersandequipmentahead这两句话我明白但是

Question

you must dimd your highlights evry suddenly if there is a oncoming car of a police
you must be dimd your highlights evry suddenly if there is a oncoming car of a policeyou must be prepared for workers and equipment ahead 这两句话我明白 但是为什么都加be 后接动词呢 you must prepared

Answer 1

用be + 动词过去时,当作形容词用,强调一种状态；如果直接用动词,强调是瞬间的动作.