托福阅读真题2
PASSAGE 41
Biological diversity has become widely recognized as a criticalconservation issue only in the past two decades. The rapid destruction of thetropical rain forests, which are the ecosystems with the highest known speciesdiversity on Earth, has awakened people to the importance and fragility ofbiological diversity. The high rate of species extinctions in these environmentsis jolting, but it is important to recognize the significance of biologicaldiversity in all ecosystems. As the human population continues to expand, itwill negatively affect one after another of Earth's ecosystems. In terrestrialecosystems and in fringe marine ecosystems (such as wetlands), the most commonproblem is habitat destruction. In most situations, the result is irreversible.Now humans are beginning to destroy marine ecosystems through other types ofactivities, such as disposal and run off of poisonous waste; in less than twocenturies, by significantly reducing the variety of species on Earth, they haveunraveled cons of evolution and irrevocably redirected its course.
Certainly, there have been periods in Earth's history when mass extinctionshave occurred. The extinction of the dinosaurs was caused by some physicalevent, either climatic or cosmic. There have also been less dramaticextinctions, as when natural competition between species reached an extremeconclusion. Only .01 percent of the species that have lived on Earth havesurvived to the present, and it was largely chance that determined which speciessurvived and which died out.
However, nothing has ever equaled the magnitude and speed with which thehuman species is altering the physical and chemical world and demolishing theenvironment. In fact, there is wide agreement that it is the rate of changehumans are inflicting, even more than the changes themselves, that will lead tobiological devastation. Life on Earth has continually been in flux as slowphysical and chemical changes have occurred on Earth, but life needs time toadapt — time for migration and genetic adaptation within existing species andtime for the proliferation of new genetic material and new species that may beable to survive in new environments.
1. What does the passage mainly discuss?
(A) The causes of the extinction of the dinosaur
(B) The variety of species found in tropical rain forests.
(C) The impact of human activities on Earth's ecosystems
(D) The time required for species to adapt to new environments
2. The word critical in line 1 is closest in meaning to
(A) negative
(B) essential
(C) interesting
(D) complicated
3. The word jolting in line 5 is closest in meaning to
(A) predicted
(B) shocking
(C) unknown
(D) illuminating
4. The author mentions the reduction of the variety of species on Earth inline 12 to suggest that
(A) new habitats can be created for species
(B) humans are often made ill by polluted water
(C) some species have been made extinct by human activity
(D) an understanding of evolution can prevent certain species fromdisappearing
5. The author mentions all of the following as examples of the effect ofhumans oil the world's
ecosystems EXCEPT
(A) destruction of the tropical rain forests
(B) habitat destruction in wetlands
(C) damage to marine ecosystems
(D) the introduction of new varieties of plant species
6. The author mentions the extinction of the dinosaurs in the secondparagraph to emphasize
that
(A) the cause of the dinosaurs extinction is unknown
(B) Earth's climate has changed significantly since the dinosaurs'extinction,
(C) not all mass extinctions have been caused by human activity
(D) actions by humans could not stop the irreversible process of a species'extinction
7. The word magnitude in line 20 is closest in meaning to
(A) concern
(B) determination
(C) carelessness
(D) extent
8. According to the passage , natural evolutionary change is different fromchanges caused by
humans in that changes caused by humans
(A) are occurring at a much faster rate
(B) are less devastating to most species
(C) affect fewer ecosystems
(D) are reversible
9. With which of the following statements would the author be most likelyto agree?
(A) Human influence on ecosystems should not be a factor in determiningpublic policy.
(B) The extinction of a few species is an acceptable consequence of humanprogress.
(C) Technology will provide solutions to problems caused by the destructionof ecosystems.
(D) Humans should be more conscious of the influence they have onecosystems
PASSAGE 41 CBBCD CDAD
托福阅读真题3
PASSAGE 42
Railroads reshaped the North American environment and reoriented NorthAmerican behavior. In a quarter of a century, claimed the Omaha Daily Republicanin 1883, they have made the people of the United States homogeneous, breakingthrough the peculiarities and provincialisms which marked separate andunmingling sections.

声明：本文是由网友投稿，文中所阐述的观点不代表本网的立场。

来源：(未知)

【傻大方】网址：/a/2020/1125/00122240.html

标题：TOEFL写作|TOEFL阅读真题( 二 )