单选题
It is believed that today's pop music can serve as a creative force ______ stimulating the thinking of its listeners.
【正确答案】
A
【答案解析】介词by常和动名词连用，说明方式、手段等。如：He taught himself to play the violin by practising all night。他通过晚上整夜地练习，自学拉小提琴。Children can learn a lot by watching TV．孩子们可以通过看电视学到好多东西。