Aravali is the oldest mountain range in the geographical structure of India which is about 870 million years old.

Devprayag: is a city located in Tehri Garhwal district of Uttarakhand state of India. It is one of the Panch Prayag and here the Alaknanda River meets the Bhagirathi River.

1. The credit for initiating modern industrialization goes to coal energy resources.

2. Coal is a solid organic substance which is used as fuel. Coal is very important as a major source of energy. 35% to 40% of the total energy used comes from coal. Other combustible and useful substances are also obtained from coal.

1. The Sadiya-Dhubri stretch of the Brahmaputra River has been declared National Waterway 2 by the National Waterways Act 1988.

2. The waterway extends from Dhubri to Sadiya for a distance of 891 km.