21.

Mention three reasons why forest must be conserved.

Name any three trees found in monsoon deciduous forests and state one use of each of these trees.

Mention two advantages of rainwater harvesting.

Why are inundation canals being converted to perennial canals ? Give two reasons. 

Give two advantages and one disadvantage that tube wells have over surface wells. 

Where are tanks most widely used in India ? Why ?

i. Name two leading states producing Manganese.

ii. Name one use of the mineral. 

i. Name two varieties of iron ore used in industry.

ii. How is the low-grade iron ore utilized ?

Give geographical reasons why :

i. Anthracite is used for domestic purposes.

ii. Oil refineries are located close to oil fields or near ports.

iii. The location of coal fields is an important factor in industrial development.

Name the mineral :

i. Which is converted to aluminium ? 

ii. Which is used in the manufacture of cement.

iii. The largest deposits of which are found in Balaghat in Madhya Pradesh.