PHP正则表达式如何匹配HTML标签

去读研的人英文肯定没问题了，那就 不帮你翻译了哈，自己看。

You get one semester hour of credit for each hour that a class meets per week for a semester. If your class meets only one hour per week for the whole semester, it would be a 1 credit class. Most classes meet for 3 hours per week for the semester and are therefor 3 credits.

Some classes are labs and labs count differently. For every 3 hours in the lab you get 1 semester hour of credit. Part of the reason is that you rarely have any additional out of class study time for a lab class (since you need the resources of the lab).

只要看unit就行了，算credit很麻烦。一般一个course有3个unit，所以算下来是差不多的。