同学你好，该知识点来自沪江网校《英语零基础直达大学六级【开学季特惠】》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。

同学你好~
The only people a painter should know are people who are beautiful, people who are an artistic pleasure to look at 这部分应该都是引文，是一整句话
(that) a painter should know 是定语从句，修饰people
who are beautiful 定语从句，修饰people
who are an artistic pleasure to look at 定语从句，修饰people

祝同学学习进步~