怎么样清除浮动？

方法1.#box{clear:both}  /*#box为浮动元素的下一个兄弟元素*/

方法2.#box{display:block;zoom:1;overflow:hidden;}/*#box为浮动元素的父元素*/

方法3.#box{zoom:1;};#box:after{display:block;clear:both;visibility:hidden;height:0;content:'';} /*#box为浮动元素的父元素*/