She is twelve years old.

她十二岁。

Alex was twelve years old.

亚历克斯当时十二岁。

Lingling is twelve years old.

玲玲十二岁。

I'm twelve years old and I'm from Beijing.

我十二岁，我来自北京。

I'm twelve years old and I have got two brothers and a sister.

我十二岁了，有两个兄弟和一个姐姐。

My life was perfect when I was twelve years old.

我十二岁的时候，我的生活很完美。

When Shakespeare was twelve years old the first public playhouse was built in London.

莎士比亚十二岁时，伦敦建造了第一座公共剧场。

When Shakespeare was twelve years old, the first public playhouse was built in London.

在莎士比亚12岁时，第一家公共剧院在伦敦建成。

What is your age? I am twelve years old.

你的年龄是多少？我十二岁。

The boy was probably twelve years old, but undersized.

这孩子大概有12岁, 不过个子没那么大.