don't be late for class.这里面怎么出现了be动词与助动词do,可以说成ian't或arn't l

don't be late for class.这里面怎么出现了be动词与助动词do,可以说成ian't或arn't l don't be late for class这句话为什么对呢?怎么be动词和助动词do同时出现了.isn't（arn' Don't( )(be)late for class ----------late for class.A Don't B Oon't be Don't again late for class be：怎么连词成句? ( )32.A:Don’t be late for class next time. Don‘t be late for class again,Tom! Don't be late for class.(改为否定句) 改为同义句：Don't be late for class Don't be late for class next time Don't be late for class again做回答 Don't be late for class again n__time