mark --- in china for ten years and now he teaches chinese in britaina\ has workedb\ workedc\ had workedd\ is working说理由!

mark --- in china for ten years and now he teaches chinese in britaina\ has workedb\ workedc\ had workedd\ is working说理由!
mark --- in china for ten years and now he teaches chinese in britain
a\ has worked
b\ worked
c\ had worked
d\ is working
说理由!

mark --- in china for ten years and now he teaches chinese in britaina\ has workedb\ workedc\ had workedd\ is working说理由!
答案选C
用过去完成时