Oh,he m___ is in his office

Oh,he m___ is in his office He is moving about in his office?. 什么is you father?He is in his office. he is at his office the light in his office is ob.he be in his of He is the busiest man______ his office?A.in B.of.应该填什么?in 还是 Where is Mr Li?___ he is in his office now.Go and find him. 3.---Is John _______ person in his office?---Yes.He is _____ Look at that m___ in brown!He is mr.Li. Mr.William is( ) work in his office Don't interrupt him.He is in his office,____himself ____work 求It is three years since he worked in his office.解释下since