用所给词的适当形式填空。

1. He wants to be a _____ (profession) singer.

2. I get to spend time _____ (do) what I love to do.

3. He has met some _____ (wonder) people at the hospital.

4. I'd like to help _____ (home) people.

5. Let's put off _____ (make) a plan.

为什么传播学传统学派的研究注重传播效果而轻视传播主体？