Hydrogen sulphide $(H_2S)$ causes:

Blue-baby syndrome is caused by:

Photochemical smog formed in congested metropolitan cities mainly consists of

Eutrophication of water bodies leading to the killing of fishes is mainly due to the non-availability of

Why is $CNG$ considered a better fuel than diesel?
$(a)$ It cannot be adulterated.
$(b)$ It takes less time to fill the fuel tank.
$(c)$ It burns more efficiently.
$(d)$ It is cheaper.
$(e)$ It is less inflammable.
Choose the most appropriate answer from the options given below:

Choose the correct statement.