He started to learn the piano when he was five years old.

题目

He started to learn the piano when he was five years old.
改成同义句
还有：
1.he was first in the competition
2.I took part in the school football team last year.
注意：
第一个用 at the age of
he started _ the piano _ _ _ five .(注意格数）

答案

He started learning the piano at the age of five.
He winned the competition.
I joined in the school football team last year.