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Subjects
Science CBSE
Class 9
Natural resources
Textbook questions
20.
NCERT Exemplar II
Exercise condition:
3
m.
1
.
One of the following factors does not lead to soil formation in nature.
Wind
Polythene bags
Water
The sun
2.
The two forms of oxygen found in the atmosphere are
water and ozone
water and oxygen
water and carbon dioxide
ozone and oxygen
3.
The process of nitrogen-fixation by bacteria does not take place in the presence of
molecular form of hydrogen
elemental form of oxygen
water
elemental form of nitrogen
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