| A | B |
|---|
| How can farmers practice soil conservation? | using contour farming and by planting rows of trees along the edges of fields |
| How can farmers preserve soil fertility? | through the use of fertilizers or through crop rotation |
| Why are forests not considered renewable resources? | original old-growth forests are lost forever when they are cut |
| What are advantages of practicing sustained yield use in forests? | trees survive, wildlife is preserved, and forests continue to produce oxygen and absorb carbon dioxide |
| What are disadvantages of practicing sustained yield use in forests? | industries based on lumber are hurt and jobs are lost |
| What can you do to help with the Earth's environmental problems? | persuade for changes industry, persuade for changes in government, reduce, reuse, recycle |
| What is reduce? | lower the amounts of disposable goods, water, and energy you use |
| What is reuse? | use things for another purpose instead of throwing them out |
| What is recyle? | items that are no longer used can be used by someone else |
| How is water quantity affected by a growing world population? | as population increases demand for water increases-deeper wells cause water to dry up |
| How are water quality affected by a growing world population? | more people causes a rise in pollutants such as sewage, increased industry/agriculture polluter water with chemicals, metals, oil |
| Why is there a concern that Earth's climate might be changing? | global warming which causes-rise in sea levels, loss of vegetation, destruction of ecosystems |
| What is the greenhouse effect? | trapping of gases in the Earth's atmosphere |
| Why is clean air a nonrenewable resource? | because it is difficult to clean polluted air |
| What are the main uses of coal? | electricity to make steel and other products |
| What are the main uses of petroleum? | gasoline, heating, electricity, petrochemicals |
| What are the main uses of natural gas? | heating and cooking |
| What are the positive aspects of nuclear energy? | clean inexpensive power source |
| What are the negative aspects of nuclear energy? | possibility of nuclear accidents and problem of disposing of nuclear waste |
| Why do some nations try to practice population control? | to limit population growth, less strain of limited resources, raise standard of living |
| What natural resources should people work together to preserve? | air, water, forests, soil, fossil fuels |
| What causes world trade but also world conflict? | unequal and uneven distribution of resources |
| Why is a hole in ozone layer a cause for concern? | it blocks harmful radiation |
