E 级和 A 级空域的区别在于，在 A 级空域，所有操作都需遵照仪表飞行规则，飞行员必须要有仪表等级，也就是说，要有操作航空仪表方面的技术和执照。

The difference between Class E and A airspace is that in Class A, all operations are IFR, and pilots must be instrument-rated, that is, skilled and licensed in aircraft instrumentation.

youdao

应该随后实现所有操作的业务逻辑。

The business logic for all the operations should then be implemented.

youdao

选择在保存时需要执行的所有操作。

Select all the actions you want to be performed on save.

youdao

So it makes sense to be able to say, look for many methods I do want to have a way of doing comparison, and I don't have to remember, at top level, what the name of the comparison method was.

所有我需要的对象进行操作，那么就可以这么说了,我想要在很多方法里面，去找做比较的方法，我并不需要记住，每一个比较的方法的名字。

麻省理工公开课 - 计算机科学及编程导论课程节选