3.The army uses a special cipher so that military messages are kept secret.
"军队使用一种特殊密码,军事电讯因此得以保密。"
4.I couldn't cipher out his motives.
我猜不出的。
5.It’s a telegram in cipher.
是密码电报。
6.Double-frequency cipher can solve the problem of multimachine mutual interference fairly good by handling the remote control and autocorrection of welding current.