clean blackboard 和clean blackboard区别,为什么要加the,

clean blackboard 和clean blackboard区别,为什么要加the, clean the blackboard clean the blackboard的意思 Who clean the blackboard yesterday? Let me clean the blackboard Clean,the,blackboard,please怎么读 to,the,told,blackboard,me,she,clean Let him______(clean)the blackboard today Please clean the blackboard的否定句 Please r_____ to clean the blackboard. Can you please____(not clean) the blackboard clean the blackboard 怎么背单词快