Question

【题目】Each class lasts 50 minutes in our school. （改为否定句）
Each class 50 minutes in our school.

Answer 1

【答案】doesn't；last
【解析】句意：在我们学校每节课持续50分钟。主语是each class, 谓语动词要用单数，lasts是行为动词，变成否定句要用助动词doesn't+动词原形，故答案为doesn't last。