In North America, a toxic weed called leafy spurge was accidentally introduced and has grown and spread rapidly, covering millions of acres in north central United States and south central Canada. Leafy spurge is generally avoided by cattle and horses and may be toxic to them. Thus, rangeland where leafy spurge has spread has been damaged by the invasion of this plant. Flea beetles alone are unlikely to eliminate all of the leafy spurge in a region. Instead, the number of leafy spurge plants and the number of flea beetles in a particular community may stabilize. At this point, the leafy spurge and flea beetle populations
A. have exhibited exponential growth followed by a crash.
B. have experienced constant growth.
C. are still experiencing exponential growth.
D. are experiencing environmental resistance.
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Water use for irrigation in the region of the Aral Sea has resulted in
A. health problems from blowing toxic dust. B. decreased water salinity. C. increased crop yields because of nutrient salts deposited on fields. D. All of the choices are correct.
Archbishop James Ussher used the Bible to construct a chronology to date the creation of the Earth to ________
A) 1776 A.D B) 46,000 B.C.E C) 79 A.D D) 4004 B.C.E
Which of the following energy forms is low-quality?
a. high-speed wind b. concentrated sunlight c. the heat dispersed in the ocean d. the energy released by burning wood e. the energy released by burning coal
____________________ act as lids on vertical air motion. When they exists near the ground, stratus clouds, fog, haze, and pollutants are all kept close to the surface
What will be an ideal response