Coal and Petroleum

Fill in the blanks in the following sentences.
(a) Coal is one of the ________ used to cook food.
(b) When heated in air, coal burns and produces mainly ________
gas.
(c) Coal tar is a black, thick ________ with an ________ smell.
(d) Petroleum, ________ and ________ are fossil fuels.
(e) Forests and coal are ________ natural resources.