题目

The boy started playing the piano when he was four years old.(同义句）
The boy started playing the piano ___ ___ ___ ___ ___ .

提问时间：2020-07-25

答案

正确答案：填at the age of four
即：The boy started playing the piano at the age of four.
翻译：这个男孩四岁时开始弹钢琴.
有不明白的请继续追问,