先来看看都有啥？


a.请选择一个背景颜色：

b.换一个方法换背景颜色：
[green] [bright green] [sea green] [red]
[magenta] [fusia] [pink] [purple]
[navy] [blue] [royal blue] [sky blue]
[yellow] [brown] [almond] [white]
[black] [coral] [olive drab] [orange]

c. 第三个方法换颜色：
variable background color changer

keep pressing buttons to change color
(the color will start as black)


d. 一个警告按钮，这可不是开玩笑！


e.这是一个危险的游戏！