we often have lessons with the windows open

we often have lessons with the windows open He often sleeps with the windows open. windows为什 We often have c lessons in the lab with the windows open,we can hear noise outside中open 为什么不用in (We should open the windows often and let the _air in)空里应填什么 We like to sleep with windows open.中with windows open做神马成分,或 i used to go to sleep with the windows open. we should sleep with the windows he would like to have the windows open. We often have lessons _____ 8A.m _____5P.m We have （） lessons in the afternoon. we have four lessons the morning.