1. html新增的标签 * 语义化（结构）标签：`header footer nav hgroup aside section article figure` * 多媒体标签：`audio video embed` * 表单标签：`email url number range Date(date month week time datetime datetime-local) search color` * 其他标签：`mark progess time ruby rt wbr canvas command deteils dateilst keygen`