nineteen

There are nineteen students enrolled in the advanced physics class.

(Chinese) 有十九名学生报名参加了高级物理课。

The treaty was signed by representatives from nineteen different countries.

(Chinese) 该条约由来自十九个不同国家的代表签署。

In many countries, you can vote at the age of nineteen.

(Chinese) 在许多国家，你可以在十九岁时投票。

When he was nineteen, he traveled across Europe by himself.

(Chinese) 他十九岁时，独自一人游遍了欧洲。