Enteramine
血清素, 5-羟色胺
🗣️ 情景例句
Typing is easy once you get the hang of it.
一旦你掌握诀窍，打字就很简单。
What time does the plane take off?
飞机何时起飞呢？
One Saturday afternoon, I hauled the machine into the garden and had a close look at it.
一个星期六的下午，我把割草机拉到了花园里，仔细检查了一番。