THE HEINEMANN TOEFL COURSE PRACTICE TEST 3 READING PART 4 (Questions 41-50)

THE HEINEMANN TOEFL COURSE

PRACTICE TEST 3

READING

PART 4 (Questions 41-50)

line 5 For all their great diversity of shapes and sizes, glaciers can be divided into two essential types: valley glaciers, which flow downhill from mountains and are shaped by the constraints of topography,  and ice sheets, which flow outward in all directions from domelike centers of accumulated ice to cover vast expanses of terrain. Whatever their type, most glaciers are remnants of great shrouds of ice that line 10 covered the earth eons ago. In a few of these glaciers the oldest ice is very ancient indeed; the age of parts of the Antarctic sheet may exceed 500,000 years. Glaciers are born in rocky wombs above the snow line, where there is sufficient winter snowfall and summer cold for snow to survive the annual melting. The long gestation period of a glacier begins with the accumulation and gradual line 15 transformation of snowflakes. Soon after they reach the ground, complex snowflakes are reduced to compact, roughly spherical ice crystals, the basic components  of a glacier.  As new layers of snow and ice, snow that survives the melting  of the previous  summer, accumulate, they squeeze out most of the air (bubbles trapped within and between the crystals below. This process of line 20 recrystallization continues throughout the life of the glacier. The length of time required for the creation of glacier ice depends mainly upon the temperature and the rate of snowfall. In Iceland, where snowfall is heavy and summer temperatures are high enough to produce plenty of meltwater, glacier ice may come into being in a relatively short time—say, ten years. In parts of line 25 Antarctica, where snowfall is scant and the ice remains well below its melting temperature year-round, the process may require hundreds of years. The ice does not become a glacier until it moves under its own weight, and it cannot move significantly until it reaches a critical thickness—the point at which the weight of the piled-up layers overcomes the internal strength of the ice and line 30 the friction between the ice and the ground. This critical thickness is about 60 feet. The fastest moving glaciers have been gauged at not much more than two and a half miles per year, and some cover less than 1/100 inch in that same amount of time. But no matter how infinitesimal the flow, movement is what distinguishes a glacier from a mere mass of ice. 41 This passage mainly discusses A the size and shape of glaciers the formation of glaciers why glaciers move two types of glaciers B C D 42 The word "constraints" in line 3 is closest in meaning to A restrictions height beauty speed B C D 43 Why does the author mention the Antarctic ice sheet in the first paragraph? A It is a slow-moving glacier. One would expect glaciers in this part of the world. It contains some of the oldest ice in existence. It is an example of a well-formed ice sheet. B C D 44 In order to describe the development of glaciers, the author uses the analogy of A birth snowflakes crystals Iceland B C D 45 The phrase "this process" in line 15 refers to A air bubbles being trapped below snow and ice compressing the ice crystals formation of ice from snow that is about to melt  melting of summer snow B C D 46 The word "trapped" in line 15 is closest in meaning to A enclosed hunted formed stranded B C D 47 According to the passage, what is one of the differences between valley glaciers and ice sheets? A Ice sheets move faster than valley glaciers. While valley glaciers flow downhill, ice sheets flow in all directions. Valley glaciers are thicker than ice sheets because of the restricting land formations. Valley glaciers are not as old as ice sheets. B C D 48 In line 24, what does "it" refer to? A glacier ice weight critical thickness B C D 49 The word "significantly" in line 24 is closest in meaning to A quickly naturally thoroughly notably B C D 50 According to the passage, the characteristic that identifies a glacier is A the critical thickness of the ice the amount of ice accumulated the movement of the ice the weight of the ice B C D

ANSWER KEY

41. В  The correct answer is (B) because after the general introduction to glaciers in paragraph one, paragraphs two, three, and four of the passage describe how glaciers are formed. The topic sentence of each of these paragraphs supports (B). Lines 8-9 state the conditions for formation of glaciers. Lines 17-18 tell about the time required for the creation of glacier ice, and lines 23-26 describe the critical thickness necessary for ice to become a true glacier and begin to move. (A) and (D) are mentioned only in paragraph one, and (C) is mentioned in paragraph 4. 42. A   Two different types of glaciers are described in lines 2-4. We infer that the effect of the topography on the shape of valley glaciers is to limit or restrict it, since the ice sheets are different in that they flow outward in all directions... and cover vast expanses of terrain. In this context, answer choice (A) restrictions is correct. 43. С   The correct answer (C) is found in paragraph one, which gives a  general definition and classification of glaciers, pointing out the age of glaciers. Lines 5-6, state that... most glaciers are remnants of great shrouds of ice that covered the earth eons ago. In lines 6-7, the author becomes more specific: In a few of these glaciers the oldest ice ... and in line 7 the author uses Antarctica as an example of an extremely old glacier. 44. A   The correct answer is (A) because an analogy is a comparison of one process to a similar, perhaps more familiar, process. In line 8 we find: Glaciers are born in rocky wombs above the snow line.... Lines 9-11 state: The long gestation period of the glacier begins... and in lines 16-17 we find... continues throughout the life of the glacier. Воrn, womb, and gestation, which means a term of pregnancy leading to birth, are used by the author to establish the lengthy process of the formation of a glacier as similar to that leading to birth. (B) and (C) are used as descriptive details in the formation of the glacier, not as analogies, and (D) is mentioned in a separate paragraph and is not related to the analogy. 45. B   The phrase "this process" refers to the process of recrystallization (lines 9-15). Clues to this reference are the sentence they squeeze out most of the air bubbles trapped within and between the crystals below; we infer that squeeze out the air bubbles is the compression of the ice crystals by the layers of firn and snow. 46. A   From the description of the process of recrystallization (lines 9-15) we deduce that the air bubbles are found within the layers of fim and snow, and cannot escape. Answer choice (A) enclosed best represents this concept. 47. B   The correct answer (B) is found by checking the facts in the passage. (B) is found in lines 2-5. (A), (C), and (D) are not mentioned in the passage. 48. B   The correct answer is (B) because the context of the sentence describes the formation of a glacier from ice; when the ice moves under its own weight, we consider that the ice has become a glacier. 49. D   The meaning of the word "significantly" can be deduced by looking at the immediate context it cannot move significantly until it reaches a critical thickness (lines 23-24), which describes the movement of the glacier. The condition for movement of the glacier, a critical thickness, suggests that before this time any movement will be minimal, or not important. Answer choice (D) notably best represents this concept. Clues from word analysis, sign meaning to notice also lead to notably as the closest meaning. 50. C   The item asks what characteristic identifies a glacier. The correct answer (C) is stated in lines 23-24: Ice does not become a glacier until... it moves under its own weight. (A), (B), and (D) are factors which contribute to causing the ice to move.