英语句中as是连词还是介词?Another policeman has been injured as fighting continued this morning.又一名警察在今天上午打斗继续过程中受了伤.

as既可以当连词 也可以当介词 本句中应该是连词,意思是 当……的时候


各举一例:
连词：（表示两件事情同时发生）当…的时候,在…的同时 If something happens as something else happens,it happens at the same time.
    介词 ：作为；当作  You use as when you are indicating what someone or something is or is thought to be,or what function they have.