Cistine
氨基酸
🗣️ 情景例句
There's always a friend around when you need one.
当你需要朋友帮忙的时候，总会有朋友在你身边的。
The stronger the motivation, the more quickly a person will learn a foreigh language.
一个人学外语的动力越强大、学得就越快。
Yes. It's time for class. Let's go.
是的。上课的时间到了。我们走吧。