The old professor,_____ in Beijing for 30 years,is on the way back to his hometown.A.to work B.having workedC.workingD.to have worked选什么为什么什么时候用一般过去时+for 一段时间?急

they decided to help the old man =the __ __ __ __ __the old man =the __ __ __ __ __ __the old man __ __ __ __ __ __ __ __(买了几张世界地图）by the old man yesterday. 英译汉Not infrequently does the old professor walk over a long distance to the library an old man __ the accident __ while he was __ __.该填什么? The old man ____(whom/that)teaches chemistry in a college is a professor. The album of painting in this museum is a gift from an old professor.如题 Do you know the speaker __ a pair of glasses is a professor __ beijing university?填空 __ __ watch it?这是什么牌子的表? the professor's wife __ in a hotel __ a senior manager The girl is __ to __ herself.C.old enough;dressD.old enough;wear The students __ old clothes will go to the farm. 英语翻译we should __ __ __ the old people 有三个空格的 英语翻译The dog can __ __ __ about 15 years old. The Professor音标?RT The old man walks __ a stick.(介词填空) The clock is old,but it is still __(use) The old man travelled abroad three time during his __ “get out,the old man said __(loud) The old lady used to go shopping every day,__?