请问,这段css代码哪里有错？为什么鼠标放上去后不能显红色？只是始终是链接的黑颜色？
a:link {
    font_size:9pt;
    color:#000000;
    text-decoration: none;
    font-family: "宋体";
    font-size: 9pt;
    line-height: 150%;
}
a:hover {
    font-size: 9pt;
    color: #ff0000;
    text-decoration: none;
    line-height: 150%;
    font-family: "宋体";
}
a:visited {
    font_size:9pt;
    color:#000000;
    text-decoration:none;
    font-family: "宋体";
    font-size: 9pt;
    line-height: 150%;
}
a:active {
    font_size:9pt;
    color:#000000;
    text-decoration: none;
    font-family: "宋体";
    font-size: 9pt;
    line-height: 150%;
}
font a:hover { font-size: 9pt; color: #ff0000; text-decoration: none}
table { background-repeat: repeat-y}
font { font-size: 9pt; text-decoration: none}
td { font-size: 9pt; text-decoration: none}
h2 { display="none" }
.word1 {
    font-family: "宋体";
    font-size: 9pt;
    line-height: 150%;
    font-weight: bolder;
    color: #000000;
    text-decoration: none;
}

因为你的a:visited设置的是黑色，访问后也就是说那些连接点击一次以后，鼠标再上放上去，就不会变成红色了，只在第一次点击时变红，你的代码很多没有必要，正如楼上所说