be off duty.duty 是宾语还是表语啊?

be off duty.duty 是宾语还是表语啊? come off duty /be off duty.意思一样吧. when will be you off duty ? 改错 in duty,on duty,off duty,duty free区别 duty i'm off duty . I have to be off duty啥意思? It is my duty to keep my classroom clean and tidy it 是形式宾语还是 on duty中的duty是动词吗 go on duty come off duty,How wonderful every day! be动词后面一定都是表语吗 更多的是宾语还是表语怎么区分?急 on duty是动词吗