Serotonin
n. 血清素\\n[化] 5-羟色胺
🗣️ 情景例句
No.
不是。
It's a shame these instructions are so complicated.
真遗憾，这些说明太复杂了。
and then there are three thousand million other Milky Ways, or galaxies, in the universe.
况且在宇宙中还有30亿个天河，即银河系。