这几个后面跟about的都是固定的搭配吗?

I wrote to you about it. I have heard about him. I spoke to you about it. I read about her. I haven't thought about it.

speak about 提及，说到
talk about 谈论，讨论
look about 环顾四周
think about 思考，考虑
bring about带来，导致
what/how about ···怎么样
walk around 四处游逛
只知道这些

有的 就是知道关于某人的某事

read about 阅读而知 think about 考虑 其他都是about作介词，表示关于。