He may fall behind other students when he come back?
请问:该句中的各"句子成分"
(1)主语——he
(2)谓语——may + fall behind
(3)宾语——other student
请问：when he come back——在句中是做“状语”吗?如果是,那他是
那一类的“状语”；如果不是那它在句中又做什么成分?