托福阅读真题练习：二氧化碳与温度关系的文本+题目+答案

托福阅读文本：

Scientists have discovered that for the last 160,000 years, at least, there has been a consistent

relationship between the amount of carbon dioxide in the air and the average temperature of the

planet. The importance of carbon dioxide in regulating the Earth's temperature was confirmed by

scientists working in eastern Antarctica. Drilling down into a glacier, they extracted a mile-long

cylinder of ice from the hole. The glacier had formed as layer upon layer of snow accumulated

year after year. Thus drilling into the ice was tantamount to drilling back through time.

The deepest sections of the core are composed of water that fell as snow 160,000 years ago.

Scientists in Grenoble, France, fractured portions of the core and measured the composition of

ancient air released from bubbles in the ice. Instruments were used to measure the ratio of certain

isotopes in the frozen water to get an idea of the prevailing atmospheric temperature at the time

when that particular bit of water became locked in the glacier.

The result is a remarkable unbroken record of temperature and of atmospheric levels of carbon

dioxide. Almost every time the chill of an ice age descended on the planet, carbon dioxide levels

dropped. When the global temperature dropped 9°F (5 °C), carbon dioxide levels dropped to 190

parts per million or so. Generally, as each ice age ended and the Earth basked in a warm

interglacial period, carbon dioxide levels were around 280 parts per million. Through the 160,000

years of that ice record, the level of carbon dioxide in the atmosphere fluctuated between 190 and

280 parts per million, but never rose much higher-until the Industrial Revolution beginning in the

eighteenth century and continuing today.

There is indirect evidence that the link between carbon dioxide levels and global temperature

change goes back much further than the glacial record. Carbon dioxide levels may have been

much greater than the current concentration during the Carboniferous period, 360 to 285 million

years ago. The period was named for a profusion of plant life whose buried remains produced a

large fraction of the coal deposits that are being brought to the surface and burned today.

托福阅读题目：

1. Which of the following does the passage mainly discuss?

(A) Chemical causes of ice ages

(B) Techniques for studying ancient layers of ice in glaciers

(C) Evidence of a relationship between levels of carbon dioxide and global temperature

(D) Effects of plant life on carbon dioxide levels in the atmosphere

2. The word "accumulated" in line 6 is closest in meaning to.

(A) spread out

(B) changed

(C) became denser

(D) built up

3. According to the passage , the drilling of the glacier in eastern Antarctica was important because

it

(A) allowed scientists to experiment with new drilling techniques

(B) permitted the study of surface temperatures in an ice-covered region of Earth

(C) provided insight about climate conditions in earlier periods

(D) confirmed earlier findings about how glaciers are formed

4. The phrase "tantamount to" in line 7 is closest in meaning to

(A) complementary to

(B) practically the same as

(C) especially well suited to

(D) unlikely to be confused with

5.According to the passage , Grenoble, France, is the place where

(A) instruments were developed for measuring certain chemical elements

(B) scientists first recorded atmospheric levels of carbon dioxide

(C) scientists studied the contents of an ice core fromAntarctica

(D) the relationship between carbon dioxide and temperature was discovered

6. According to the passage , scientists used isotopes from the water of the ice core to determine

which of following?

(A) The amount of air that had bubbled to the surface since the ice had formed

(B) The temperature of the atmosphere when the ice was formed

(C) The date at which water had become locked in the glacier

(D) The rate at which water had been frozen in the glacier

7. The word "remarkable" in line 14 is closest in meaning to

(A) genuine

(B) permanent

(C) extraordinary

(D) continuous

8. The word "link" in line 23 is closest in meaning to

(A) tension

(B) connection

(C) attraction

(D) distance

9. The passage implies that the warmest temperatures among the periods mentioned occurred

(A) in the early eighteenth century

(B) 160,000 years ago

(C) at the end of each ice age

(D) between 360 and 285 million years ago

10.According to the passage , the Carboniferous period was characterized by

(A) a reduction in the number of coal deposits

(B) the burning of a large amount of coal

(C) an abundance of plants

(D) an accelerated rate of glacier formation

11. The passage explains the origin of which of the following terms?

(A) glacier (line 5)

(B) isotopes (line 11)

(C) Industrial Revolution (line 21)

(D) Carboniferous period (lines 26)

托福阅读答案：

CDCBC BCBAC D

以上就是小编为大家整理的托福阅读100篇真题练习：二氧化碳与温度关系的文本、题目以及答案，大家在托福阅读考试进行备考的过程当中也可以拿这些题目来进行练习，相信对于你的托福阅读考试成绩提升会很有帮助。最后，小编预祝大家托福考试能取得理想的成绩。

托福阅读文本：

Naturalists and casual observers alike have been struck by the special relationship between

squirrels and acorns (the seeds of oak trees). Ecologists, though, cannot observe these energetic

mammals scurrying up and down oak trees and eating and burying acorns without wondering

about their complex relationship with trees. Are squirrels dispersers and planters of oak forests or

pesky seed predators? The answer is not simple. Squirrels may devour many acorns, but by storing

and failing to recover up to 74 percent of them as they do when seeds are abundant, these arboreal

rodents can also aid regeneration and dispersal of the oaks.

Their destructive powers are well documented. According to one report, squirrels destroyed

tens of thousands of fallen acorns from an oak stand on the University of Indiana campus. A

professor there estimated that each of the large white oaks had produced between two and eight

thousand acorns, but within weeks of seed maturity, hardly an intact acorn could be found among

the fallen leaves.

Deer, turkey, wild pigs, and bears also feed heavily on acorns, but do not store them, and are

therefore of no benefit to the trees. Flying squirrels, chipmunks, and mice are also unlikely to

promote tree dispersal, as they often store seeds in tree cavities and

underground burrows. Only

squirrels — whose behavior of caching (hiding) acorns below the leaf litter — often promote

successful germination of acorns, and perhaps blue jays, important long-distance dispersers, seem

to help oaks spread and reproduce.

Among squirrels, though, there is a particularly puzzling behavior pattern. Squirrels

pry off

the caps of acorns, bite through the shells to get at the nutritious inner kernels,

and then discard

them half-eaten. The ground under towering oaks is often littered with thousands of half-eaten

acorns, each one only bitten from the top. Why would any animal waste so much time and energy

and risk exposure to such predators as red-tail hawks only to leave a large part of each acorn

uneaten? While research is not conclusive at this point, one thing that is certain is that squirrels do

hide some of the uneaten portions, and these acorn halves, many of which contain the seeds, may

later germinate.

托福阅读题目：

1. What does the passage mainly discuss?

(A) The ecology of oak trees

(B) Factors that determine the feeding habits of Squirrels

(C) Various species of animals that promote the dispersal of tree seeds

(D) The relationship between squirrels and oak trees

2. The word "they" in line 7 refers to

(A) oak forests

(B) acorns

(C) squirrels

(D) predators

3.According to the passage , what do squirrels do when large quantities of acorns are available?

(A) They do not store acorns.

(B) They eat more than 74 percent of available acorns.

(C) They do not retrieve all the acorns that they have stored.

(D) They hide acorns in tree cavities.

4. The word "estimated" in line 11 is closest in meaning to

(A) commented

(B) judged

(C) observed

(D) discovered

5. Why does the author mention "the University of Indiana campus" in line 10 -11?

(A) to provide evidence that intact acorns are hard to find under oak trees

(B) to indicate a place where squirrels can aid seed dispersal of oaks

(C) to argue in favor of additional studies concerning the destructive force of squirrels

(D) to support the claim that squirrels can do great damage to oak stands

6. It can be inferred from paragraph 3 that chipmunks do not aid in the dispersal of oak trees

because

(A) they store their acorns where they cannot germinate

(B) they consume most of their stored acorns

(C) their stored acorns are located and consumed by other species

(D) they cannot travel the long distance required for dispersal

7.According to the passage , which of the following do squirrels and blue jays have in common?

(A) They travel long distances to obtain acorns.

(B) They promote the reproduction of oak trees.

(C) They bury acorns under fallen leaves.

(D) They store large quantities of acorns.

8. The phrase "pry off" in line 21 is closest in meaning to

(A) swallow

(B) remove

(C) squeeze

(D) locate

9. The word "littered" in line 22 is closest in meaning to

(A) covered

(B) displayed

(C) fertilized

(D) planted

10. According to the passage , scientists cannot explain which of the following aspects of squirrel

behavior?

(A) Where squirrels store their acorn caches

(B) Why squirrels prefer acorns over other seeds

(C) Why squirrels eat only a portion of each acorn they retrieve

(D) Why squirrels prefer acorns from a particular species of oak trees

托福阅读答案：

DCCBD DBBAC

以上就是小编为大家整理的托福阅读100篇真题练习：松鼠和橡子的文本、题目以及答案，大家在托福阅读考试进行备考的过程当中也可以拿这些题目来进行练习，相信对于你的托福阅读考试成绩提升会很有帮助。最后，小编预祝大家托福考试能取得理想的成绩。