1. Coal is one of the ________ used to cook food.

2. When heated in air, coal burns and produces mainly ________ gas.

3. Coal tar is a black, thick ________ with an ________ smell.

8. All the things that are required to fulfil one’s need are called _______.

9. Anything that burns to produce energy is called a ___________.

10. ___________ is a black-coloured hard substance that mainly contains carbon.

11. The time period taken to complete the  process of carbonisation is called ___________.   

12.___________ is the most inferior and softest form of coal.

13. The least polluting fuel for vehicle is ___________.

14. The major fossil fuels are ___________ and ___________.

15. The major component of CNG is ___________.

16. Destructive distillation of coal is done at ___________.

17. Petroleum is a mixture of different ___________.

18. ___________ is another name for petroleum.

19. Devices that consume less energy are ______ and __________ lights.

20. Forests are ___________ natural  resources.

21. Petra means _______ and oleum means ______.

22.  ________ is the leading producer of crude oil.

23. When heated in air, coal burns and produces mainly _________ gas.

24. We should use ___________ instead of individual vehicles.

25. Separation of different constituents of petroleum is

called ___________.

26.The slow process of conversion of dead vegetation into coal is called________.

27. Coal and petroleum are formed from the dead remains of organisms and are known as __________.

28. The black thick liquid with ______ smell is known as coal tar.

29.  During the processing of coal to get coke, coal tar and __________ are also obtained.

30. The process of separating the various constituents of petroleum is known as __________.

31.  Excessive burning of fossil fuels is a major cause of __________.