说明：  KML文件格式详细介绍。KML全称是Keyhole Markup Language KML，是一个基于XML语法和文件格式的文件，用来描述和保存地理信息如点、线、图片、折线并在Google Earth客户端之中显示， (KML以前的版本能够被Google Earth读取并保存为KML 2.0) KML 2.0提供以下功能
(KML file format is described in detail. KML stands for Keyhole Markup Language KML, an XML grammar and file format of the file-based, used to describe and save geographic information, such as points, lines, images, line, and being displayed in Google Earth client, (KML previous version can Google Earth to read and save it as a KML 2.0) KML 2.0 provides the following features)