知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。W3Schools is optimized for Understanding and training. Examples could possibly be simplified to enhance studying and Understanding.知乎，让每一次点击都充满意义 —— 欢迎来到知乎，发现问题背后的世界。Very uncomplicate