System.Xml.XmlDocument，什么是缓存外部依赖DTD的最佳方法？

I'm loading valid XHTML into an XmlDocument, but it takes 2 seconds to load. I've found that if I drop the DTD, it's instant, but then I have to replace   to  , etc. The number of declared HTML entities is large, so I feel the DTD should be loaded. So what is the easiest way to pre-load the DTD with minimal manual labor? Perhaps if I could, say, put the DTD into the assembly as a resource file and inject it in..? Any suggestions?I'm loading valid XHTML into an XmlDocument, bu