Historians and philosophers agree that ever since the
development of agriculture, human beings have had art effect on the natural
habitat (动植物生息地) of many plants and animal species. As human populations have
increased, as many as 6,000 species are disappearing each year. A number 10,000
times greater than before man appeared on the planet. In one day alone, say
scientists, some 45 kinds of plants and animals will die, some 17,500 species
will be wiped out. In 1977, the United States Congress took an
important step to help the ever - increasing number of endangered species.
With the enforcement of the Endangered Species Act, some species have
gained more public recognition than others. Elephants and whales, for example,
have received far more media attention than have the smaller, less known, and
less attractive species that are also endangered. Yet it is the tiny species,
such as bugs and bacteria, that keep the planet in balance. Scientists are
becoming even more concerned with the fact that without equal concern for these
species, the planet’s biological diversity will be destroyed, leaving us with a
loss of potential new food and drugs. On the other hand, some
scientists argue that the extinction issue is being exaggerated(夸大), and that
people are "crying wolf" by describing the loss of species as more alarming than
it really is. History proves that every species will eventually become extinct.
Evolution of species, they say, naturally involves the extinction of species;
man has no control. In addition, many people point to the fact
that the world is already lacking in resources, food, and adequate health care.
Concerned more with economic survival, they ask whether it is, in fact,
realistic to make a fuss over saving the elephant or other species that may
become extinct many years from now, when people have families to feed tomorrow.
These people question a law that puts the continuation of lower forms of life
above man’s own survival. 1. The issue: To what extent we should try to
(46) or allow for man’s development. 2. Proponents’ ( 支持者)
( of saving endangered species) arguments : a. The extinction of
plants and animals is (47) before man appeared on the
planet. b. Tiny species keep the earth in balance. c. Man
needs (48) for food and drugs. 3. Opponents’ (反对者) ( of
saving endangered species) arguments: a. Proponents exaggerate the
case. b. Species (49) e. Man’s need
(50)