用以下句型造句 （英语）

题目

用以下句型造句 （英语）
第一个句型：
is one of the + 最高级+名词复数
第二个句型：
It is + 形容词+ for sb.+ to do sth.
第三个句型：
It is a good idea to do sth.

答案

China is one of the biggest countries in the world.
It's dangerous for you to play with fire.
It is a good idea to have a walk in the sunny day.