(~s)
A ~ is a group of radio waves of similar length which are used for particular types of radio communication.
N-COUNT
(~s)
A ~ is a group of radio waves of similar length which are used for particular types of radio communication.
N-COUNT
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012