She's the middle child of three.

三个孩子，她是老二。

《牛津词典》

He is the author of three books on art.

他写了三本艺术专著。

《牛津词典》

It was very strong, made of three solid planks of wood.

它非常结实，是用三块厚木板做成的。

《柯林斯英汉双解大词典》

The American Lung Association said Pittsburgh was last in the nation in one of three measures of air quality.

VOA: special.2009.07.13

A studio of three hours' lecture in a large lecture hall, and two hours of recitation in groups of thirty.

在一个大的讲堂的教室里,讲三个小时讲座，并以三十人为一组,进行两小时背诵。

麻省理工公开课 - 媒体、教育、市场课程节选

But, if you look more carefully, you will find that this is a blend of three different forms of carbon.

但是，如果你们再认真一点，会发现,它是三种形式的碳的混合物。

麻省理工公开课 - 固态化学导论课程节选

It is made up of three historic palazzo, and both Depp and Jolie have stayed here.

BBC: Hollywood and Venice: A love story

An early second-half trade of three more penalties helped the Saints increase their lead.

BBC: Sale Sharks 29-21 Northampton Saints

The result arrested a run of three games without a win for the Gunners.

BBC: Arsenal's spirit delights Wenger