固網電信

landline (fixed-line) telecommunications

hard / strong / solid / sure / assuredly / undoubtedly / of course / indeed / admittedly

net / network

lightning / electricity / electric (bound form) / to get (or give) an electric shock / phone call or telegram etc / to send via telephone or telegram etc

telecommunications

letter / mail / CL:封[feng1] / to trust / to believe / to profess faith in / truthful / confidence / trust / at will / at random