Exocycloida
外环形棘皮目
🗣️ 情景例句
You should use 'officer' to address a policeman.
你应该用 'officer' 来称呼警察。
I don't seem to have any luck today.
我今天运气不好。
The two brothers look very much alike.
这兄弟俩看上去很相像。