Google是否仅接受.txt扩展名的站点地图？

I have finalized working on my Asp.Net 4.0 website. Now that i am to publish it by next few days, i am finding resources that can help me better rank my site on popular search engines. My site displays both static and dynamic contents. For dynamic contents i will be generating dynamic sitemap each week. My problem is that i read on google webmaster website that google accepts sitemaps only with .txt extension. (I have finalized working on my Asp.Net 4.0 webs