31.
The method of soil conservation in which rocks are piled up to slow down the flow of water which prevents gullies and further soil loss is called

32.
The World's largest bio-fuel plant has been established with a production capacity of 100 million liters per year, is located in

33.
Rio Summit is associated with

34.
The method of soil conservation in the coastal and dry regions where rows of trees are planted to check the wind movement to protect soil cover is called

35.
The radiant energy received by the Earth from the sun is

36.
Which has the maximum rate of deforestation?

37.
Which of the following aquatic plant is effective in preventing the water-pollution caused by industrial waste?