Most elements in the topic DTD contain a set of universal attributes that enable the elements to be used as selectors, filters, content referencing infrastructure, and multi-language support.
主题DTD中的多数元素都包含一组统一的属性，使元素可以用作选择器、过滤器、内容引用基础设施和多语言支持。
A simple selector is either a type selector or universal selector followed immediately by zero or more attribute selectors, ID selectors, or pseudo-classes, in any order.
一个简单选择符或者是一个类型选择符，或者是一个全局选择符，紧跟在后的是零个或多个属性选择符，ID选择符或伪类，次序任意。
应用推荐