<html><head><style>a:link{background-color:yellow;}</style></head><body><a href="https://www.w3school.org.cn">W3Sschool</a><a href="http://www.google.com">Google</a><a href="http://www.wikipedia.org">Wikipedia</a><p><b>注释：</b>:link 选择器为未被访问过的链接设置样式。</p></body></html>