_____________ gas turns colourless nitrogen monoxide into brown fumes of nitrogen dioxide.
Which of the following gas does not contribute to the formation of acid rain ?
(a) nitrogen monoxide
(b) carbon monoxide
(c) sulphur dioxide
(d) nitrogen dioxide
On a cold winter night, the persons sleeping in a room with closed door and windows with a coal fire burning inside may die due to the excessive accumulation of :
(b) nitrogen dioxide
(c) carbon dioxide
(d) carbon monoxide