71.
The Red Data book which lists endangered species is maintained by

72.
Human population growth curve is a:

74.
_______ tree is known as "flame of the forest"?

75.
From which language did the word Tsunami originate?

76.
The source of aerosol in upper atmosphere is

77.
Noise is measured using sound meter and the unit is

78.
The concept of ecological pyramid was first proposed by

79.
When it is January and winter in the Northern Hemisphere, it is ______and ________in the Southern Hemisphere.

80.
The World Wetlands Day is celebrated on ________