we must keep classroom clean.这句中的must是什么词,做什么成份?

we must keep classroom clean.这句中的must是什么词,做什么成份? We must ___(keep) the classroom clean. 初中英语变为被动语态we must keep our classroom clean we must keep our classroom clean改被动语态 We must keep our classroom clean The sentence stucture here we must keep the classroom clean的句子基本结构 We must keep our classroom clean and tidy句子结构 We must keep our classroom (clean) every day 英语：keep用法1.We must keep the classroom .A.clean B.to clean C. we must keep our classroom( ). we must clean the classroom every day 同义句 we must clean the classroom every day同义句转换