”我七岁被选入校队，开始学球练球，小学时每天练习近三个小时“用英文怎么翻译？

不知道你练的是什么球 暂时用篮球来代替好了。下面是比较浅的一种翻译，纯英文哦，不是【中式】的。

When I was seven,I was on the school team and started learning to play basketball and practicing it.When I was in primary school,I practiced playing basketball about three hours every day.

I was elected into school team in 7 and began to study and train.
I practiced every day for nearly three hours in primary school.

was seven elected school team has begun to study the ball Lian Qiu, elementary school to practice every day for nearly three hours