题目内容：

The great variety of reasons people have for buying one product rather than another are investigated by the _____ people in order to produce efficacious commercials.
A:advertised B:advertisement C:advertising D:advertiser
请问填哪个 求详解

优质解答

B advertisement

追问：

advertising advertised 这两个为什么不行呢

追答：

名词是可以修饰名词的。