下列样式定义字体间距为0.5倍间距、水平左对齐、垂直顶端对齐、有下划线,正确的定义是:( )
①
p{text-decoration:underline;letter-spacing:0.5em;vertical-align:top;text-align:left;}
②
p{text-decoration:0.5em;letter-spacing:underline;vertical-align:top;text-align:left;}
③
p{text-decoration:left;letter-spacing:top;vertical-align:0.5em;text-align:underline;}
④
p{text-decoration:underline;letter-spacing:0.5em;vertical-align:left;text-align:top;}