86. Which of the following is not a source of surface water pollution?
a) Municipal sewage
b) Agricultural runoff
c) Natural weathering of rocks
d) Industrial discharges
87. What is the name of the process by which water is naturally purified as it percolates through layers of rock and sediment?
a) Filtration
b) Desalination
c) Distillation
d) Reverse osmosis
88. Which of the following is not a strategy for reducing water use in agriculture?
a) Implementing drip irrigation systems
b) Using drought-resistant crops
c) Increasing the use of fertilizers and pesticides
d) Practicing crop rotation
89. Which of the following is not a type of water use in industry?
a) Cooling
b) Washing
c) Drinking
d) Manufacturing
90. What is the name of the process by which water is naturally purified as it percolates through layers of rock and sediment?
a) Filtration
b) Desalination
c) Distillation
d) Reverse osmosis
