Improved water quality.
Regulated stream flow.
All of these answers
None of these answers
A factory pollutes a river as much as the law allows.
Some levels of pollution are life threatening.
Some activities harm the environment, but others do not.
Irrigated cropland can be ruined by salinization.
Cropland can decrease biodiversity.
Maintenance of maximum biological diversity.
Production of high-quality timber.
A long-term ecologically oriented approach.
To grow and harvest monoculture forests.
Multiple use of forest for timber, watershed protection and recreation.
Coniferous forest soil.
Deciduous forest soil.
Tropical forest soil.
Air and water quality.
All of these answers.
Extensively patrol the accessible popular areas.
Offer permits to selected area for those who have demonstrated wilderness skills.
Leave some areas undisturbed by humans
Allow citizens to camp anywhere at their own risk.
Limit number of people using sites at any one time.
High cost of gasoline
State and local zoning
Availability of mortgages
Government loan guarantees to veterans
Ample land for expansion
Solar energy and gravity.
Solar energy and the moon.
Solar energy and the mechanical energy.
Mechanical and chemical energy.
Chemical energy and the moon.
When environmental conditions are changing rapidly, a generalist is usually better off than a specialist.
The fundamental niche of a species is the full range of physical, chemical, and biological factors it could use if there were no competition.
The competitive exclusive principle states that no two species with the same fundamental niche can indefinitely occupy the same habitat.
Interspecific competition is competition between two members of the same species.
Intraspecific competition is competition between two members of the same species.
The amount of heat trapped in the troposphere depends on the concentrations of greenhouse gases.
The greenhouse effect is a new theory that explains the warming of the atmosphere.
Heat trapped by greenhouse gases keeps the planet warm enough for life.
The two predominant greenhouse gases are water vapor and carbon dioxide.
It has been confirmed by numerous lab experiments and measurements of atmospheric temperatures at different altitudes.
Lack of requirements of massive amounts of fossil fuels.
Conserving and building topsoil.
Lack of use of many artificial chemicals.
Switch from fossil fuels to nuclear fuels.
Increase the efficiency of energy use.
Plant trees to trap more carbon dioxide.
Slow population growth.
Freedom to go where you want when you want.
Provisions of jobs.
Convenience of use.
The amount of solar energy reaching Earth's surface is dependent on latitude.
Hot air rises.
Air at the lower latitudes tends to cool and fall or sink downward.
Cool air is denser than warm air.
Cool air falls.
All of these answers.
Preventing dehydration by giving infants sugar and salt in water.
Giving vitamin A supplements.
Providing family planning services.
Giving iron supplements.
IUD plus spermicide.
An oral contraceptive.
A hormonal implant.
A condom (good brand).
The rhythm method.