The self study class is half empty.

自习课教室只有一半人数。

Hey, guys. Come in back for self study, please.

嘿，大家，请进来上自习课。

After classes finish, there are two hours of self study.

下课后还有两个小时的自习时间。

When you learn new words in class, or during self study, it's in your short-term memory.

当你在课堂上或自学期间学习新单词的时候，那就是在你的短期记忆中发生的。

But I spent my year productively by reading up on new technologies, self studying, and trying to challenge myself with small projects.

但我通过阅读新技术、自学， 度过了富有成效的一年， 并尝试通过小项目挑战自己。