将div浮动到父容器中，并设置其样式如下：
.aParent div { float: left; clear: none;}<div > <div> <span>source list</span> <select size="10"> <option /> <option /> <option /> </select> </div> <div> <span>destination list</span> <select size="10"> <option /> <option /> <option /> </select> </div></div>
