81.
The word Tsunami is derived from two Japanese words

82.
The proper order from shortest to longest wavelength is:

83.
DDT is a ______________ pollutant

84.
Noise is _______________

85.
What is UNCED?

86.
What is the official name of IUCN?

87.
What is the most important factor for the success of animal population?

88.
_________ is the element used to produce nuclear energy

89.
Carbon dioxide is called greenhouse gas because it is

90.
Which of the following enhances soil fertility?