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》

The lectureship is tenable for a period of three years.

讲师这一职务任期三年。

《牛津词典》

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