zend framework tutorial，运行例子，报如下的错误：
The server encountered an internal error and was unable to complete your request. Either the server is overloaded or there was an error in a CGI script.
查看apache错误日志文件error.log，有如下错误：
Invalid command 'RewriteEngine', perhaps mis-spelled or defined by a module not included in the server configuration
解决办法：
打开httpd.conf，找到LoadModule rewrite_module modules/mod_rewrite.so，取消其前面的注释即可。