centos无法启动httpd服务

centos无法启动httpd服务

# systemctl start httpd
Job for httpd.service failed. See 'systemctl status httpd.service' and 'journalctl -xn' for details.

systemctl status httpd.service
httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled)
   Active: failed (Result: exit-code) since Wed 2015-04-15 17:28:43 CST; 26s ago
  Process: 1301 ExecStop=/bin/kill -WINCH ${MAINPID} (code=exited, status=0/SUCCESS)
  Process: 1300 ExecStart=/usr/sbin/httpd $OPTIONS -DFOREGROUND ( code=exited, status=1/FAILURE)
Main PID: 1300 (code=exited, status=1/FAILURE)


Apr 15 17:28:43 iZ94hj21pncZ systemd[1]: Starting The Apache HTTP Server...
Apr 15 17:28:43 iZ94hj21pncZ httpd[1300]: AH00558: httpd: Could not reliably determine the server's fully qualified domain name, using 10.169.141.134. Set ...is message
Apr 15 17:28:43 iZ94hj21pncZ httpd[1300]: (98)Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
Apr 15 17:28:43 iZ94hj21pncZ httpd[1300]: no listening sockets available, shutting down
Apr 15 17:28:43 iZ94hj21pncZ httpd[1300]: AH00015: Unable to open logs
Apr 15 17:28:43 iZ94hj21pncZ systemd[1]: httpd.service: main process exited, code=exited, status=1/FAILURE
Apr 15 17:28:43 iZ94hj21pncZ systemd[1]: Failed to start The Apache HTTP Server.
Apr 15 17:28:43 iZ94hj21pncZ systemd[1]: Unit httpd.service entered failed state.
Hint: Some lines were ellipsized, use -l to show in full.


报错是无法启动apache的http  server
我现在主机装的是nginx，应该不用装apache才对吧
刚开始接触服务器，不太懂
求指教