2021年托福阅读模拟试题及答案(卷三)

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2021年托福阅读模拟试题及答案（卷三）

托福阅读文本：

There are only a few clues in the rock record about climate in the

Proterozoic eon. Much of

our information about climate in the more recent periods of

geologic history comes from the fossil

record, because we have a reasonably good understanding of the

types of environment in which

many fossil organisms flourished. The scarce fossils of the

Proterozoic, mostly single-celled

bacteria, provide little evidence in this regard. However, the rocks

themselves do include the

earliest evidence for glaciation, probably a global ice age.

The inference that some types of sedimentary rocks are the result of

glacial activity is based on

the principle of uniformitarianism, which posits that natural

processes now at work on and within

the Earth operated in the same manner in the distant past. The

deposits associated with present-day

glaciers have been well studied, and some of their characteristics

are quite distinctive. In

2.3-billion-year-old rocks in Canada near Lake Huron (dating from

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the early part of the

Proterozoic age), there are thin laminae of fine-grained sediments

that resemble varves, the annual

layers of sediment deposited in glacial lakes. Typically, present-day

varves show two-layered

annual cycle, one layer corresponding to the rapid ice melting and

sediment transport of the

summer season, and the other, finer-grained, layer corresponding to

slower winter deposition.

Although it is not easy to discern such details in the Proterozoic

examples, they are almost

certainly glacial varves. These fine-grained, layered sediments even

contain occasional large

pebbles or "dropstones," a characteristic feature of glacial

environments where coarse material is

sometimes carried on floating ice and dropped far from its source,

into otherwise very fine grained

sediment. Glacial sediments of about the same age as those in

Canada have been found in other

parts of North America and in Africa, India, and Europe. This

indicates that the glaciation was

global, and that for a period of time in the early Proterozoic the

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Earth was gripped in an ice age.

Following the early Proterozoic glaciation, however, the climate

appears to have been fairly

benign for a very long time. There is no evidence for glaciation for

the next 1.5 billion years or so.

Then, suddenly, the rock record indicates a series of glacial episodes

between about 850 and 600

million year ago, near the end of the Proterozoic eon.

托福阅读题目：

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

(A) How patterns in rock layers have been used to construct

theories about the climate of the

Proterozoic age

(B) What some rare fossils indicate about glacial conditions during

the late Proterozoic age

different parts of the world

(D) The number of glacial episodes that the Earth has experienced

since the Proterozoic age

2.According to the passage , the fossil record of the Proterozoic eon

(A) highly regarded because it preserves the remains of many kinds

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of organisms

(B) less informative than the fossil record of more recent periods

(D) more useful to researchers than otheraspects of the rock record

3. The word "scarce" in line 4 is closest in meaning to

(A) ancient

(B) tiny

(D) rare

4. It can be inferred from the passage that the principle of

uniformitarianism indicates that

(A) similar conditions produce similar rock formations

(B) rock layers in a given region remain undisturbed over time

(D) each continent has its own distinctive pattern of sediment layers

5. The word "resemble" in line 14 is closest in meaning to

(A) result from

(B) penetrate

(D) replace have similar origins

6.According to the passage , the layers in varves are primarily

formed by

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(A) fossilized bacteria

(B) pieces of ancient dropstones

(D) annual cycles of sediment transport and deposition

2021年托福阅读PASSAGE 33 试题及答案

2021年托福阅读PASSAGE 33

试题及答案

PASSAGE 33

Researchers in the field of psychology have found that one of the best ways to make

an important decision, such as choosing a university to attend or a business to invest

in, involves the utilization of a decision worksheet. Psychologists who study

optimization compare the actual decisions made by people to theoretical ideal

decisions to see how similar they are. Proponents of the worksheet procedure believe

that it will yield optimal, that is, the best decisions. Although there are several

variations on the exact format that worksheets can take, they are all similar in their

essential aspects. Worksheets require defining the problem in a clear and concise way

and then listing all possible solutions to the problem. Next, the pertinent

considerations that will be affected by each decision are listed, and the relative

托福考试阅读模拟题包括解析

1 / 9

2021 年托福考试阅读模拟试题及答案解析〔 1 〕

托福阅读原文

Protection of Plants by Insects

【 1】Many plants - one or more species of at least68

different families - can secrete nectar even whenthey have no

blossoms, because they bear extrafloral nectaries (structures

that producenectar) on stems, leaves, leaf stems, or other

structures.These plants usually occur where antsare abundant,

most in the tropics but some in temperate areas. Among those

of northeasternNorth America are various plums, cherries,

roses, hawthorns, poplars, and oaks. Like floralnectar,

extrafloral nectar consists mainly of water with a high content

of dissolved sugars and, in some plants, small

amounts of amino acids. The extrafloral nectaries of

some plants areknown to attract ants and other insects,

but the evolutionary history of most plants with

2021年托福试题阅读理解模拟题考点分析(卷十)

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2021年托福试题阅读理解模拟题考点分析（卷十）

Title：The Cambrian Explosion

The earliest fossil evidence for eukaryotes complex organisms

whose cells contain a distinct nucleus dates to only about 1.2 billion

years ago. The fossil record suggests that animal evolution progressed

slowly, with relatively little change seen between fossils from 1.2 billion

years ago and those from a half-billion years later. But then something

quite dramatic happened as can be judged by the many different animal

groups that suddenly appear in the fossil record.

Biologists classify animals according to their basic body plans. For

example, the basic body plan shared by mammals and reptiles is

fundamentally different from that of insects.Animals are grouped by

2021年托福阅读PASSAGE 3 试题及答案

2021年托福阅读PASSAGE 3

试题及答案

PASSAGE 3

The Native Americans of northern California were highly skilled at basketry, using the reeds,

grasses, barks, and roots they found around them to fashion articles of all sorts and sizes —

not only trays, containers, and cooking pots, but hats, boats, fish traps, baby carriers, and

ceremonial objects.

Of all these experts, none excelled the Pomo — a group who lived on or near the coast

during the 1800's, and whose descendants continue to live in parts of the same region

to this day. They made baskets three feet in diameter and others no bigger than a

thimble. The Pomo people were masters of decoration. Some of their baskets were completely

covered with shell pendants; others with feathers that made the baskets' surfaces as soft as

the breasts of birds. Moreover, the Pomo people made use of more weaving techniques than

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2021年托福阅读模拟试题及答案(卷三)

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2021年托福阅读PASSAGE 33 试题及答案

托福考试阅读模拟题包括解析

2021年托福试题阅读理解模拟题考点分析(卷十)

2021年托福阅读PASSAGE 3 试题及答案

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