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TOEFL Directory > TOEFL writing > TOEFL Reading Class Unit 2_Passage 10_Question 100-110
TOEFL Reading Class Unit 2_Passage 10_Question 100-110
You have about 15 minutes to finish this passage.
First,use about 3-4 minutes to read the passage, try to understand the main idea of this passage.
Don't read it so slowly or try to remember all details.You need to do "fast reading",and "scan" the passage.
Second, read questions 1-11, and with questions you go back the passage again and look for correct answers.
Questions 100-110
Passage 10
Within the earth's crust, rock exhibits a plastic or fluid character if subjected to great forces. This is evident from observations of rock layers that have been compressed horizontally into what are called folds. These folds, or wrinkles, may be less than a fraction of an inch wide or they may be several miles in width. The earth's crust in many places appears to have been compressed into upward and downward folds. The upward arch of a fold is called an anticline, and the downward part, or the trough, is called a syncline. The anticline is generally the more accessible part of the fold in terms of observation because the syncline is buried beneath the surface. The anticline, being forced upward, is subject to erosion, and often the rock in the anticline is so disrupted, cracked, and distorted in the folding process that it may be readily eroded away. When this happens, the upper parts of the adjacent syncline may be exposed, and the structure of a region can be more carefully studied. Oil-well drilling records, highway cuts, and stream erosion provide other sources of information through which a fairly satisfactory idea of the arrangement of the rock layers in syncline can be obtained.
Folding in the earth's crust partly accounts for the formation of many mountain ranges, such as the Appalachian Mountains. The folds in these mountains were originally formed during the Appalachian Revolution, roughly 200 million years ago. In recent geologic periods these folds have become stabilized, that is, they have not been significantly further distorted, pushed together, or pulled apart. Erosion has removed most of the ridges and filled the troughs to the extent that many of the present ridges are formed by erosion-resistant rock that at one time lay in the lower part of a fold.
Before the process of folding was understood, many types of rock layering presented a difficult puzzle for geologists until the early twentieth century. However, using the concept of folding has allowed the geologists to work out quite satisfactory structures, even for the most complex folds.
100. What does the passage mainly discuss?
a) Methods of observing rock folds
b) The characteristics of rock folding
c) The development of mountain ranges
d) The composition of the earth's crust
101. The phrase subjected to in the passage is closest in meaning to
a) shaped by
b) placed under
c) made of
d) prone to
102. According to the passage, which of the following causes rock layers to fold?
a) Drilling for oil
b) Horizontal compression
c) Stream erosion
d) Highway cuts
103. Synclines are not usually observable because they are typically
a) part of an upward arch
b) subject to distortion
c) a fraction of an inch wide
d) under the ground
104. The word adjacent in the passage is closest in meaning to
a) buried
b) complex
c) nearby
d) layered
105. The phrase accounts for in the passage is closest in meaning to
a) disguises
b) questions
c) analyzes
d) explains
106. Why does the author mention he Appalachian Mountains in paragraph 2 ?
a) To give an example of how
folding can affect mountains
b) To indicate the amount of time
mountains take to develop
c) To introduce the effects of
erosion on mountains
d) To demonstrate that folding
is unique to mountains
107. The word roughly in the passage is closest in meaning to
a) equally
b) thoroughly
c) approximately
d) mainly
108. In can be inferred from the passage hat the Appalachian Mountains' present-day ridges and troughs
a) will become higher than they are currently
b) are made of rock different from that found in other mountains
c) are older than those of most mountain ranges
d) are not undergoing as much change now as they did in the past
109. The word puzzle in the passage is closest in meaning to
a) situation
b) game
c) question
d) solution
110. Which of the following statements is supported by the passage?
a) The Appalachian Revolution that created the Appalachian Mountains was an unusual geologic event.
b) Earthquakes tend to be limited to areas in which rock folds are numerous.
c) Some areas of the Earth's surface are not subject to the process of folding.
d) Studying the rock folds in a region will provide information about the geologic development of the region.
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