同学你好，该知识点来自沪江网校《实用英语口语【生活美语随到随学班】》的课程，想要更系统的学习，欢迎进入课程学习。不仅可以和更多的同学一起学习，而且还有老师、助教随时的学习指导和知识点解答哦。

同学好，
For many of those kids, dating is 【pretty much】all they care about.
主干是dating is all.
all (that) they care about, 定语从句修饰all,
pretty much相当于almost, 字典上有这个用法
这里的意思是: 他们几乎只关心约会这件事。

pretty much/well
almost
差不多；几乎全部地，几乎完全地
I've pretty much finished here. 我这儿基本上完成了。
She knows pretty well everything there is to know on the subject. 对这个问题她几乎了如指掌。
https://dictionary.cambridge.org/dictionary/english-chinese-simplified/pretty?q=pretty+much%2Fwell

周末愉快。