thirteen

十三

Six plus seven equals thirteen, as any child can tell you.

六加七等于十三，任何小孩都答得出来。

十三岁

She started learning the violin at thirteen.

她十三岁开始学小提琴。

十三的、十三个

There are thirteen students waiting outside the classroom.

教室外面有十三个学生在等。

十三岁的

My nephew is thirteen years old this month.

我姪子这个月满十三岁。