He was twelve years old. Experts at the National Institutes of Health say good dental care starts at birth.

VOA: special.2009.03.11

Louis XIV when he was a kid, he was about twelve or thirteen years old, he lived in Paris.

在他还是个十二,三岁的孩子的时候,他住在巴黎

耶鲁公开课 - 欧洲文明课程节选

I did have a friend who was beat up by about twelve or thirteen kids who were all between ten and eleven years old,

我有个朋友曾被十二三个孩子殴打，都在十岁和十一岁之间。

大城市是否危险？ - SpeakingMax英语口语达人

He wanted to create a series for girls who were about ten to twelve years old.

VOA: special.2009.08.24

When she was only twelve years old, Mary became the first person to find the almost complete skeletons of several animals that no longer existed on Earth.

VOA: special.2009.05.13

She was twelve years old. Schools then were not designed for wheelchairs.

VOA: special.2010.07.28

The Admongo website is aimed at children eight to twelve years old.

VOA: special.2010.06.04

His father died when he was twelve years old.

VOA: special.2009.05.31

The oldest child was twelve years old.

VOA: special.2010.02.02