He is working for a big firm and he has visited a great number of different places in Australia.以前听老师讲过,用and 连接的前后句的时态应该是一样的,为什么这句话前后句的时态不同呢?

he is working for a big firm as an engineer 句中的working是什么时态 he is working for a big firm?he is working for a big firm可以不可以 改成he is working in a big firm?为什么要用for呢? he is working for a big firm.和he works for a big firm.有什么区别? he is working ( )a model plane now. a.on b.at c.for d.in Tim is working for a big firm.He is working for a big ( ) A society B company C factory在线等!新概念2上的! tim is working for a big firm.he is working for a big __.(society/company/factory/store)翻译?分别么意思?为什么? He is working for a big company.He is looking for a pen .work for 和look for都是固定搭配吗? is he (tire)after working for a long time用所给词填空 it is neccessary that he (take)_____a good rest after working for a long time he is working () a car factory 现在完成时填写： He is working for a big firm and he aleady ____(visit) a great number . He is working for a big company.He is looking for a pen.这 两个句子怎样划分句子成分?look for 和wor work for work at work in1.he is working for a big firm2.tony worked in a lawyer's office years ago3.he is now working at a bank请问可不可以互换,如果不可以的话是为什么? he is working for a big firm as an engineer这句话的as用对没有? be known to选择并翻译?He is known ____ here for more than ten years.A.to work B.to have been working C.for working D.working after working for five hours,he()a rest 英语词汇题2.The only for his strange behavior is that he’s been working too hard.2.The only for his strange behavior is that he’s been working too hard.a.explanation b.explaining c.explain d.explained l______the retired teacher is still working hard for the people .A.though old he is B.unless he is old C.old ao he is D.however he is old我觉得应该选A但答案是C,