About two-fifteenths of the students took part in the competition.

大概十五分之二的学生参加了这次比赛。

You are the fifteenth student I teach.

你是我教的第十五名学生。

Our class is the fifteenth in this competition.

我们全班是这个比赛的第十五名。

The Moon Festival is the fifteenth day of August.

中秋节是（农历）八月的第十五天

They can push down the thirteenth partial and bring up the fifteenth and thereby change the sound of a clarinet into a French horn.

他们可以压低第十三分音，或者提高第十五分音，从而将单簧管的声音变成圆号的。

'Fifteenth,' said the March Hare.

“是十五日。”三月兔说。

How many fifteenth century Milanese artists can you name?

有多少15世纪的米兰艺术家你能叫出他们的名字？

Something was happening in Florence in the fifteenth century.

在15世纪的佛罗伦萨一定有什么事情发生。

Mary McLeod Bethune was the fifteenth child born out of seventeen.

玛丽·麦克劳德。白求恩的家里有十七个孩子，她排行十五。