默认地，浏览器使用980像素宽的视见区或逻辑尺寸。

By default, the browser USES a viewport, or logical dimension, of 980 pixels wide.

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iUI使用这来决定将哪个列表放置在iPhone视见区的正文部分。

IUI USES this to determine which list to place in the body of the iPhone viewport.

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如果在页面中selected设置为true的位置存在一个HTML标记，CSS会使用CSS声明display： block将它赋值到视见区的整个正文。

If there is an HTML tag in the page where selected is set to true, the CSS assigns that to the entire body of the viewport using the CSS declaration display: block.

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