1) The future worldwide use of irrigation:
A) is expected to double in the next 20 years due to increasing demands for food
B) is limited by the availability of freshwater, waterlogging, and salinization of soils
C) depends on new technologies to extract more groundwater
D) will require increased reliance on new hydrogen technologies to produce freshwater
16) The development of new varieties of grain crops increased productivity by increasing the:
A) surface area of the leaves of the plants
B) size of the roots and ability to absorb water
C) strength of the stems to support more grains
D) size and number of seeds
2) In the last 50 years, the greatest progress in addressing worldwide hunger and malnutrition came from the:
A) use of better transportation methods to export grain more efficiently
B) development and use of new varieties of high-yielding wheat and rice
C) reduced reliance on pesticides, herbicides, and chemical fertilizers
D) widespread use of sustainable irrigation methods
3) Although the Green Revolution has greatly reduced world hunger and malnutrition, it has:
A) doubled the amount of land used to raise crops
B) not significantly increased the productivity of modern agriculture
C) required high levels of increasingly expensive fertilizer and pesticides
D) contributed significantly to the destruction of the ozone layer
4) Radiation exposure immediately around a properly functioning nuclear power plant is about
A) less than 1% of natural background exposure.
B) double normal environmental background exposure.
C) 10 times higher than normal environmental background exposure.
D) 100 times higher than normal environmental background exposure.
5) Nuclear bombs rely upon:
A) a domino effect that causes the nuclear fission of uranium-235 in less than a second
B) a domino effect that causes the nuclear fusion of uranium-235 in less than a second
C) an instantaneous fission of uranium-235 under extreme pressures
D) an instantaneous fusion of uranium-235 under extreme pressures
6) Enrichment of nuclear fuel:
A) increases the relative concentration of uranium-235 to only 3-5% to avoid any possibility of nuclear explosion at higher percentages
B) increases the relative concentration of uranium-235 to 30-50% to avoid a nuclear explosion at higher percentages
C) decreases the relative concentration of uranium-235 from 60% to only 3-5% to avoid a nuclear explosion at higher percentages
D) decreases the relative concentration of uranium-235 from 100% to 30-50% to avoid a nuclear explosion at higher percentages
7) The actual fission reactions that release energy in a nuclear power plant are about:
A) two-thirds from uranium-235 and one-third from uranium-239
B) one-third from uranium-235 and two-thirds from uranium-239
C) two-thirds from uranium-235 and one-third from plutonium-239
D) one-third from uranium-235 and two-thirds from plutonium-239
8) A self-amplifying reaction and a nuclear explosion in a nuclear power plant are prevented in large part by:
A) the regular addition of uranium-239 to the fuel
B) control rods that absorb extra neutrons
C) the production of plutonium-239
D) fuel rods that absorb tremendous amounts of heat
Unit 3 Examination
9) Compared to a nuclear plant, a coal-fired plant:
A) releases more than 100 times more radioactivity because of radioactive elements in coal.
B) requires much less mining and results in fewer mining deaths.
C) contributes to acid rain, and a nuclear plant does not.
D) emits much less carbon dioxide.
10) About how much of the sun’s radiation would strike the Earth if the Earth did not have its atmosphere?
A) about 10 times more
B) about twice as much
C) it would be about the same
D) about half as much
11) With all of the sun’s energy striking the Earth every second of every day, why doesn’t the Earth overheat and kill us all?
A) The Earth is so large and dense that it absorbs all of this heat.
B) The Earth is overheating regionally, melting rocks into the lava of volcanoes.
C) The Earth maintains a balance by radiating this heat back into space.
D) The atmosphere of the Earth prevents the solar radiation from reaching the Earth’s surface.
12) The thinning of the troposphere away from the equator is primarily a result of:
A) land masses moving towards the poles
B) shifting of the continental plates due to plate tectonics
C) differences in solar energy striking the Earth
D) the number of clouds in the mesosphere and thermosphere
13) The effect of the 2008 recession has
A) speeded up the flight from inner cities to suburbs.
B) made existing properties more valuable.
C) greatly slowed the suburban building boom and the purchase of new houses.
D) reversed the movement to suburbs, increasing the pressure to find housing in the inner city.
Unit 4 Examination
14) Over the past 60 years, as people moved from U.S. cities to suburbs, the people that were left behind in the cities were primarily
A) older, poor people representing ethnic minorities.
B) younger, wealthy people representing ethnic minorities. C) older and wealthy Caucasians.
D) younger Caucasians.
15) _________________ ranges from supporting and voting for particular candidates to expressing your support for particular legislation through letters or phone calls.
A) Lifestyle choices
B) Membership in nongovernmental organizations
C) Political involvement
D) None of the above