The different types are designated by the letters A, B and C.

不同的类型分别用字母A、B和C标明。

《牛津词典》

He says that brain change is strongest when a) you are interested in and like what you are learning, b) you are in control of what you learn and c) you get challenging tasks that make you think hard.

他说，当你 a）对你正在学习的东西感兴趣并且喜欢它，b）你能控制你所学的东西，c）你接受有挑战性、让你努力思考的任务时，大脑的变化是最剧烈的。

youdao

A heptavalent vaccine protecting against meningitis A and C was licensed in 2007.

预防甲型和丙型脑膜炎的七价疫苗于2007年获得许可。

youdao

The wind came again. Finally,the men heard a new sound C the sound of waves breaking and crashing on the shore.

VOA: special.2010.03.06

So let's just compare. Let's compare what C happened in path A to what happened in paths B and C. Yes?

我们比较一下沿,路径A和路径B和,所发生的事有什么不同，什么？

麻省理工公开课 - 热力学与动力学课程节选

So, the first thing we do is put two electrons between h and c, and then two electrons between c and n.

那么，我们先在氢和碳之间放两个电子，然后在碳和氮之间再放两个电子。

麻省理工公开课 - 化学原理课程节选

That, in turn, boosted understanding of hepatitis B and C and still other viruses.

FORBES: The Golden Age of Antiviral Drugs

The following rally allowed one to define a longer-term flag formation (lines a and c).

FORBES: Using Fibonacci to Trade Flag Patterns

The Nets were leading 81-73 early in the fourth after 3-pointers by Wallace and C.

WSJ: Nets beat Bulls 95-92, force Game 7