My heart beats bouncing ball, thump, thump, as Grade Six students run quickly down the court.

当六年级的学生快速地跑到球场上来的时候,我的心跟着球一起跳动起来, 一下, 两下.

互联网

The mid - 19 th century, Europeans mastered the rubber, which can only make the bouncing ball.

19世纪中叶, 欧洲人掌握了橡胶技术之后, 才做出了能弹跳的球.

互联网