In those days most people left school when they were only fifteen years old.

　　那時(shí)候，大多數(shù)人上學(xué)只上到十五歲。

　　He is ten years old.

　　他十歲了。

　　You don't look 15 years old

　　你看上去不像15歲。

　　I'd say he was 25 to 30 years old.

　　我猜他在25至30歲之間。

　　There have been many changes in recent years.

　　近幾年發(fā)生了許多變化。

　　Those were the best years of my life.

　　那些年是我一生最幸福的時(shí)光。