(~s)
Smog is a mixture of fog and smoke which occurs in some busy industrial cities.
Cars cause pollution, both ~ and acid rain.
N-VAR
(~s)
Smog is a mixture of fog and smoke which occurs in some busy industrial cities.
Cars cause pollution, both ~ and acid rain.
N-VAR
Collins COBUILD. Толковый словарь английского языка для изучающих язык Коллинз COBUILD (международная база данных языков Бирмингемского университета) . 2012