reach fifteen 到十五岁。

　　到十五岁

　　By the age of fifteen

　　双语对照

　　双语例句

　　1

　　他妻子的年龄比他小十二到十五岁。

　　His wife was twelve or fifteen years younger than he was.

　　2

　　到十五岁，他已经掌握小提琴的技巧。

　　Fifteen he had mastered violin technique.