我今年12岁用英语怎么表达

　　years old的例句：

　　I'll be 26 years old next Friday.

　　我下周五就26岁了。

　　Nora thought he was seventeen years old.

　　诺拉觉得他有17岁。

　　It's almost 15 years old. It isn't worth having it repaired.

　　这东西差不多15年了。不值得送去修了。

　　These rocks have been dated radiometrically at two billion years old.

　　经辐射能探测，这些岩石形成于20亿年前。