Read the passage and answer the question. "Clear radio communication depends less on volume than on structure. An operator who begins every transmission by naming the station being called, and only then giving his or her own call sign, allows the listener to orient before the content of the message arrives. Short sentences, standard phrasing, and a brief pause between thoughts reduce the chance that a weak signal will erase a critical word. Experienced operators also repeat numbers digit by digit, since a single misheard figure can send a response team to the wrong location. None of these habits requires expensive equipment; they require only discipline and practice." Which statement best expresses the main idea of the passage?