11. Unhealthy soil management methods
a) degrades soil quality c) enhances erosion.
b) causes soil pollution
d) all
12. Most common toxic soil pollutants may arise from
a) leaching of wastes from landfills
b) Application of animal dung to the soil
c) acid rain
d) decaying plants
13. Which of the following human activities does not increase the level of heavy metals in soils?
a) Industrial and agricultural activities
b) Waste incineration
c) Combustion of fossil fuels
d) None
14. Organic pollutants enter the soil through
a) bedrock weathering
b) decomposition of plant and animal debris
c) atmospheric deposition
d) all of the above
15. Pollution of agricultural soils by heavy metals can
a) increase agricultural yield by providing plants sufficient amount of essential metals
b) introduce toxic heavy metals into the food chain
c) increase the number of soil microorganisms which can boost agricultural yield
d) all of the above​