影音先锋男人站-免费的av网站-无码精品人妻一区二区-丝袜ol美脚秘书在线播放-日韩精品福利-午夜免费观看视频-日韩少妇av-国产福利小视频在线观看-体内精69xxxxxx-好av-夜夜欢视频-乳色吐息在线看-国产最爽的乱淫视频国语对白-高潮一区二区-四虎影像

Program overview

In recent years, economic development has promoted the improvement of China's scientific and technological level. With the progress and development of science and technology, communication tools have become more and more developed. At present, interphone, pager, wireless phone and other communication tools have increased sharply, forming an all-weather and all-round communication network, especially in modern enterprises, the lack of radio communication means is unimaginable. These communication tools provide convenience in leadership, command and business contact. However, the electromagnetic wave interference generated by radio communication poses a threat to the production safety and stable operation of enterprises, causing hidden dangers.