Atmosphere of big/metrapoltian cities are polluted most by :

Atmosphere of big/metropolitan cities is polluted most by

Atmosphere of big/metropolitan cities is polluted most by (a) Automobile exhausts (b) Pesticide residue (c) Household waste (d) Radioactive fall -out

Atmosphere of cities and metropolitan cities is polluted most by

Atmosphere of big cities is polluted most by

Atmosphere of big cities is polluted most by

Generally speaking, the atmosphere in big cities is polluted mostly by :