内容提示：

1）多锻炼大脑，使大脑活跃：可以尝试学一门新的语言或玩一种新的乐器(musical instrument)；

2）记忆东西时，要集中精神(focus on)；

3）重复要记住的内容，帮助记忆；

4）过健康的生活：均衡饮食，充足睡眠均对大脑有好处。

This is thing in the world!

— No, it's so boring. I would like _______ a film.

—Oh, its improved system gives people a ________ ride even on mountain roads.

—Let's collect and put them in the right place _______ they can be used conveniently.

—Why not search it on the Internet? It's much easier and faster.

This book is .