about是在此处是介词还是副词?

about是在此处是介词还是副词? about 这里是 介词还是副词? for是介词还是副词 in是副词还是介词 down是副词还是介词 look around ,throw about,这里的around 和about 是副词,还是介词 It take me about half an hour.这里的about是副词还是介词? I haven't thought it through properly.through在这里是介词还是副词,此句如何 it sent sparks down to the ground...请问down在此是介词还是副词啊?怎么判断? 在put on中,on是副词还是介词? turn off的off在这里是介词还是副词? such as是介词还是副词短语