电话机电子密码锁吴汉清电话是人们最常用的通信工具。电话用户普遍关心的一个问题是，电话机被他人任意拨打市内和长途电话，这种现象防不胜防．致使电话费居高不下。为此，用户可以向电话局申请呼出限制，但必须每月交纳使用费，且只能限制长途电话呼出，使用也不方便。... Telephone electronic password lock Wu Hanqing phone is the most commonly used communication tools. One of the common concerns of telephone users is that it is hard to detect when the telephone is arbitrarily dialed into the city and long distance. Resulting in high telephone bills. To this end, users can apply for outgoing calls to the Bureau, but must pay a monthly fee, and can only limit long-distance phone calls, use is not convenient. ...