The average height of himalayas rises to an average of ________ meters
A. 2000
B. 4000
C. 6000
D. 8000
Skin cancer known as Melanoma associated with ____________?
A. ozone accumulation
B. ozone depletion
C. acid rain
D. allergens
Where ozone layer lies from the earth surface?
A. 10 to 20 km
B. 20 to 30 km
C. 30 to 40 km
D. 40 to 50 km
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