What are the ads for?整句的意思是广告的用途/目的是什么?这里的for表用途/目的,也就是为了……。E.g. :the advertisements is used for promoting the products.(广告是用于促销产品的) FOR的用法挺多的,常用如下:(1)因为,由于 for this reason (2) 表示时间\距离长度; for three days; He ran for three miles. (3) 为了 :What do you come here for? (4) 表示等价交换: He sold his house for 30,000 doll