css 中的class类为什么有2个名字？还是什么意思？_html/css_WEB-ITnose

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<style type="text/css">    .m{background-color: red;}    .xj{background-color: blue;}    .xskd{background-color: mediumaquamarine;}</style><div class="m xj xskd">    <p>Hello</p>
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                            <a href="/ai/1104">阿里云-虚拟数字人</a>
                            <p>阿里云-虚拟数字人是什么？ ...</p>
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                                <span>2</span>
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