576.
you must have dialed the wrong number.你一定打错电
话了。
577. i dialed the right number,but nobody 
answered.
我拨的号码正确，但是没有人接听。
578. the telephone is ringing,would you answer it,please?
电话铃响了，你能接下电话吗？
579. would you like to leave a message? 你想留下什么口信儿吗？
580. who is this?i don’t recognize your voice.
你是谁？我听不出你的声音。