You can add a pressed button state with CSS by styling the active pseudo-class of the link in question.

你可以通过配置CSS中链接的active伪类来添加一个按下的按钮状态。

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Especially with the popularization of the TV and rise of Internet, the environmental question of the pseudo is more and more outstanding, drawing people's extensive concern too.

特别是随着电视的普及和互联网的兴起，拟态环境问题越来越突出，也引起人们的广泛关注。

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PROFESSOR: Great question. So the question is, how do you choose an algorithm, why would I choose to use a pseudo-polynomial algorithm when I don't know how big the solution is likely to be, I think that's one way to think about it.

教授：问得好，所以问题是，你怎样选择算法，为什么当我,不知道解决方案会有多大的时候,我要选伪多项式算法呢，我想这是一种思考问题的方式。

麻省理工公开课 - 计算机科学及编程导论课程节选