A.#box{width:100px;height:50px;}
B.#box{width:100px;height:50px; position:absolute;}
C.#box{width:100px;height:50px; position:static;}
D.#box{width:100px;height:50px; position:relative;}

A.body：color=black
B.{body；color：black}
C.body{color：black}
D.{body：color=black（body）}