The teacher required that no one ________ late for class．
A.beB.must beC.should have beenD.was在线课程A
动词demand，require，suggest，insist，advise，order等后接宾语从句时，从句中谓语动词应使用虚拟语气，即“should+动词原形(do/be done)”，should可省略。