16. What is the greenhouse effect?
a) The trapping of heat in the Earth’s atmosphere
b) The conversion of carbon dioxide into oxygen
c) The process of cleaning polluted air
d) The protection of the ozone layer
17. What is the main cause of acid rain?
a) Forest fires
b) Volcanic eruptions
c) Industrial emissions
d) Sunlight
18. What are the effects of noise pollution on human health?
a) Hearing loss
b) Improved sleep quality
c) Increased concentration
d) Decreased stress levels
19. What is biomagnification?
a) The process of increasing the population of species
b) The accumulation of pollutants in the food chain
c) The natural growth of plants
d) The restoration of degraded ecosystems
20. How do greenhouse gases contribute to global warming?
a) By reflecting sunlight
b) By depleting the ozone layer
c) By trapping heat in the atmosphere
d) By preventing air pollution
