为什么实体& eacute;无效，而实体& lt;是吗

我正在查看xml解析器 System.Xml.Resolvers.XmlPreloadedResolver 在dtds方面带来了什么，而我感到困惑的是实体& lt; 被xml读取器识别，但实体& eacute; 不能识别。

I'm looking at what the xml resolver System.Xml.Resolvers.XmlPreloadedResolver brings to the table in terms of dtds and i'm stumped by the fact that the entity < is recognized by the xml reader but not the entity é.

    private static void Main(string[] args)
    {
        string invalidContent = "<?xml version=\"1.0\" encoding=\"utf-8\"?><key value=\"char &eacute; invalid\"/>";
        string validContent = "<?xml version=\"1.0\" encoding=\"utf-8\"?><key value=\"char &lt; valid\"/>";

        XmlDocument xmlDocument = new XmlDocument();

        var xmlReaderSettings = new XmlReaderSettings()
        {
            DtdProcessing = DtdProcessing.Parse,
            XmlResolver = new XmlPreloadedResolver(XmlKnownDtds.All),
            ProhibitDtd = false
        };

        using (XmlReader reader = XmlReader.Create(new StringReader(invalidContent), xmlReaderSettings))
        {
            xmlDocument.Load(reader); // reference to undeclared entity 'eacute'
        }

        using (XmlReader reader = XmlReader.Create(new StringReader(validContent), xmlReaderSettings))
        {
            xmlDocument.Load(reader); //
        }
    }

在XmlPreloadedResolver内部检查，我可以看到 XmlKnownDtds.All 应该带入xhtml-lat1.ent文件，其中包含紧急实体以及许多其他实体。知道为什么我会看到这种行为吗？

Checking inside the XmlPreloadedResolver i can see that the XmlKnownDtds.All should bring in the xhtml-lat1.ent file which contains the eacute entity, along with many others. Any idea why i'm seeing this behavior?