托福阅读常考话题及练习题推荐四：冰川（2）

► Paragraph 1：During the peak of the last ice age, northeast Asia (Siberia) and Alaska were connected by a broad land mass called the Bering Land Bridge. This land bridge existed because so much of Earth’s water was frozen in the great ice sheets that sea levels were over 100 meters lower than they are today. Between 25,000 and 10,000 years ago, Siberia, the Bering Land Bridge, and Alaska shared many environmental characteristics. These included a common mammalian fauna of large mammals, a common flora composed of broad grasslands as well as wind-swept dunes and tundra, and a common climate with cold, dry winters and somewhat warmer summers. The recognition that many aspects of the modern flora and fauna were present on both sides of the Bering Sea as remnants of the ice-age landscape led to this region being named Beringia.

1. The word “remnants” in the passage is closest in meaning to

A. remains

B. evidence

C. results

D. reminders

► Paragraph 2：It is through Beringia that small groups of large mammal hunters, slowly expanding their hunting territories, eventually colonized North and South America. On this, archaeologists generally agree, but that is where the agreement stops. One broad area of disagreement in explaining the peopling of the Americas is the domain of paleoecologists, but it is critical to understanding human history: what was Beringia like?

2. The word “domain” in the passage is closest in meaning to

A. field of expertise

B. challenge

C. interest

D. responsibility

Paragraph 3：The Beringian landscape was very different from what it is today. Broad, windswept valleys; glaciated mountains; sparse vegetation; and less moisture created a rather forbidding land mass. This land mass supported herds of now-extinct species of mammoth, bison, and horse and somewhat modern versions of caribou, musk ox, elk, and saiga antelope. These grazers supported in turn a number of impressive carnivores, including the giant short-faced bear, the saber-tooth cat, and a large species of lion.

3. According to paragraph 3, all of the following are true of the Beringian landscape EXCEPT:

A. There was little vegetation.

B. The mammal species there all survived into modern versions.

C. The climate was drier than it is today.

D. There were mountains with glaciers.:

4. The purpose of paragraph 3 is to

A. contrast today’s Beringian landscape with other landscapes in the American continent

B. describe the Beringian landscape during the last ice age

C. explain why so many Beringian species became extinct during the last ice age

D. summarize the information about Beringia that historians agree on

► Paragraph 4：The presence of mammal species that require grassland vegetation has led Arctic biologist Dale Guthrie to argue that while cold and dry, there must have been broad areas of dense vegetation to support herds of mammoth, horse, and bison. Further, nearly all of the ice-age fauna had teeth that indicate an adaptation to grasses and sedges; they could not have been supported by a modern flora of mosses and lichens. Guthrie has also demonstrated that the landscape must have been subject to intense and continuous winds, especially in winter. He makes this argument based on the anatomy of horse and bison, which do not have the ability to search for food through deep snow cover. They need landscapes with strong winds that remove the winter snows, exposing the dry grasses beneath. Guthrie applied the term “mammoth steppe” to characterize this landscape.

5. The word “continuous” in the passage is closest in meaning to

A. unpredictable

B. very cold

C. dangerous

D. uninterrupted

6. Which of the sentences below best expresses the essential information in the highlighted sentence in the passage? Incorrect choices change the meaning in important ways or leave out essential information.

A. According to biologist Dale Guthrie, mammal species require broad areas of vegetation to survive.

B. Dale Guthrie is an Arctic biologist who argued that broad areas of dense vegetation were surely enough to attract mammals such as mammoth, horse, and bison to Beringia.

C. Dale Guthrie argued that Beringia, though cold and dry, must have had enough dense vegetation to support the herds of mammoth, horse, and bison that lived there.

D. As long as Beringia was cold and dry, argued Dale Guthrie, dense vegetation grew in order to support the herds of mammoth, horse, and bison—the mammal species present there.

7. According to paragraph 4, Guthrie believes that the teeth of ice-age fauna support which of the following conclusions?

A. Large mammals would not have been able to survive in the Beringian landscape.

B. Grasslands were part of the Beringian landscape.

C. Strong winds exposed dry grasses under the snow.

D. Horses and bison did not have the ability to search for food through deep snow cover.

8. According to paragraph 4, which of the following statements is true of the relationship between ice-age Beringian animals and their environment?

A. When present in sufficient quantities, lichens and mosses provide enough nutrients to satisfy the needs of herds of large mammals.

B. The anatomy of certain animals present in that environment provides information about the intensity of winds there at that time.

C. The structure of the teeth of most ice-age fauna indicates that they preyed on animals such as the mammoth, horse, and bison.

D. Horses and bison are large enough that their feet can easily penetrate deep snow and uncover areas where they can feed on plant material.