使用百分比描述尺寸
<img src="https://img2018.cnblogs.com/blog/1122471/201902/1122471-20190222185756735-1641099963.png" width="60%">

使用宽度描述尺寸
<img src="https://img2018.cnblogs.com/blog/1122471/201902/1122471-20190222185756735-1641099963.png" width="600">

没有尺寸描述
<img src="https://img2018.cnblogs.com/blog/1122471/201902/1122471-20190222185756735-1641099963.png">
或

