Preventology
[医] 牙病预防学
🗣️ 情景例句
He's gone out of business.
他失业了。
What's the purpose of your visit?
你旅行的目的是什么？
Litter baskets have been placed under the trees, but people still throw their rubbish everywhere.
树下都已设置了废物筐，但是人们仍到处扔垃圾。