console 命令行工具 X clear

console

<img class="normal" src="//www.w3school.com.cn/i/eg_smile.gif" />
<br />
<img class="big" src="//www.w3school.com.cn/i/eg_smile.gif" />
<br />
<img class="small" src="//www.w3school.com.cn/i/eg_smile.gif" />

img.normal {
  height: auto
}

img.big {
  height: 50%
}

img.small {
  height: 10%
}