Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth's ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulunerable to UV-B radiation. In addition, their relatinous eggs lack the protection of leathery or hard shells, Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.
Each of the following, if true, would strengthen the argument EXCEPT:
A. Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes.
B. Amphibian populations are declining far more rapidly than are the populations of nonamphibian species whose
tissues and eggs have more natural protection from UV-B.
C. Atmospheric ozone has been significantly depleted above
all the areas of the world in which amphibian populations are declining.
D. The natural habitat of amphibians has
not become smaller over the
past century.
E. Amphibian populations have declined continuously
for the last 50 years.-- by 会员 blvicky (2009/12/27 21:50:05)
Amphibian populations are declining in numbers worldwide. Not coincidentally, the earth's ozone layer has been continuously depleted throughout the last 50 years. Atmospheric ozone blocks UV-B, a type of ultraviolet radiation that is continuously produced by the sun, and which can damage genes. Because amphibians lack hair, hide, or feathers to shield them, they are particularly vulunerable to UV-B radiation. In addition, their relatinous eggs lack the protection of leathery or hard shells, Thus, the primary cause of the declining amphibian population is the depletion of the ozone layer.
Each of the following, if true, would strengthen the argument EXCEPT:
A. Of the various types of radiation blocked by atmospheric ozone, UV-B is the only type that can damage genes.
B. Amphibian populations are declining far more rapidly than are the populations of nonamphibian species whose
tissues and eggs have more natural protection from UV-B.
C. Atmospheric ozone has been significantly depleted above
all the areas of the world in which amphibian populations are declining.
D. The natural habitat of amphibians has
not become smaller over the
past century.
E. Amphibian populations have declined continuously
for the last 50 years.-- by 会员 blvicky (2009/12/27 21:50:05)
BCDE都跟原文由相关联的。
A的,取非,对原文不加强也不削弱,只是重复了原文的意思
-- by 会员 prayer (2009/12/28 12:24:08)