短语讲解：

1. The other meaning is closely related. As you move through school, you cross off a series of achievements: grade school, middle school, high school, and college.

cross off 划掉
例句：Please cross the crab off my bill and I'll leave now.
请在账单内剔除这个菜然后给我结账。

2. So, when people used to speak of getting a diploma, they said they "graduated from college."

speak of 说到; 谈到
例句：Reading is the only hobby I can speak of.
读书是我唯一值得一提的爱好。

3. we think about the student and the university.

think about 考虑…; 捉摸…
例句：I want you to have time alone to think about yourself.
我想让你有机会单独想想自己。