Pentacyclic
五环的
🗣️ 情景例句
If you know a man's last name, address him as 'Mr.'.
如果你知道一个男性的姓， 应该用 'Mr。' 来称呼他。
Do not run too fast after gain.
不要见利就拼命追。
Somebody's knocking at the door. I'll answer it.
有人在敲门，我去开。