DIAGNOSTIC TEST (PART 1) CAMBRIDGE PREPARATION FOR THE TOEFL® IBT TEST

 

CAMBRIDGE PREPARATION FOR THE TOEFL® IBT TEST DIAGNOSTIC TEST (PART 1)

 

READING SECTION Directions In this section, you will read three passages and answer reading comprehension questions about each passage. Most questions are worth one point, but the last question in each set is worth more than one point. The directions indicate how many points you may receive. You have 60 minutes to read all of the passages and answer the questions. Some passages include a word or phrase followed by an asterisk (*). Go to the bottom of the page to see a definition of these words or phrases.   Question 1-12 Causes of Ice Ages Geologists have shown that for about 80 percent of the past 2.5 million years, ice-age  conditions have prevailed on the Earth’s surface. During the past one million years, increased  glacial conditions have run in cycles of approximately 100,000 years. Many different factors may contribute to these increases in glaciation at regular intervals  throughout Earth’s more geologically recent history. The three most prominent factors  probably relate to the amount of sunlight that reaches the Earth. This varies over time for  three main reasons. First, the planet wobbles* as it spins, due to the pull of the sun and  moon. Furthermore, the Earth tilts* on its axis and the degree of tilt changes over time.  Finally, the orbit of the Earth around the sun is elliptical and the length of the major axis of  the ellipse changes over a period of about 100,000 years. A mathematician named Milutin  Milankovitch discovered in the 1930s that the pattern of insolation, or sunlight, predicted by  these eccentricities in the Earth’s movement matched the period of the last several eras of  intense glaciation. These Milankovitch insolation cycles were  the dominant theory in ice-age research  for much of the twentieth century despite the fact that the match between periods of peak  insolation and most intense glaciation were not exact. For example, a cycle of 400,000 years  predicted by the Milankovitch theory has never shown up in the climate records obtained  through the study of microfossils deposited on the sea floor. Also, recent analysis has shown  that the insolation theory predicts peaks of sunlight at intervals of 95,000 and 125,000  years. Climatological data does not support this predicted sunlight peaking. Other damaging  evidence was the indication of a precisely measured sudden rise in temperature at a  water-filled cave in Nevada, which preceded the increase in solar radiation that was  supposed to cause it. These and other problems with the Milankovitch cycles led some researchers to seek  alternative explanations for the cyclic arrival of extended ice ages. In the 1990s, it was  discovered that the orbital inclination of the Earth to the sun and planets could also be  responsible for climate changes. If we imagine a flat plane with the sun in the center and  the planets revolving around it, the Earth slowly moves in and out of the flat plane by a few  degrees, repeating the cycle every 100,000 years. Two scientists, Muller and MacDonald,  have proposed that it is this orbital inclination which is ultimately responsible for the periods  of glaciation and warming. They argue that because of the oscillation, the Earth periodically  travels through clouds of debris, in the form of dust and meteoroids. Such debris could  reduce the amount of solar energy reaching the surface of our planet, thus plunging it into  regular cold periods. The advantage of this theory is that it is not confronted with several of the problems  associated with the Milankovitch theory. In particular, the new theory fits well with the analysis of ocean sediments taken from eight locations around the world. This analysis yielded data  clearly showing the peak of the last several ice ages with a period of 100,000 years and  corresponding to the periods when the Earth’s oscillating inclination takes it through clouds of  extraterrestrial debris. However, many researchers in this field are not yet persuaded by the inclination  hypothesis. The main problem is that the amount of dust that falls to the ground when the  Earth travels through space debris is relatively  small – not enough to produce radical climate  changes. Volcanic eruptions, for example, release much greater amounts of ash and dust  and have relatively little effect on climate. Supporters have countered that the by-products  created by the dust as it vaporizes on entering the atmosphere cause subtle changes to the  energy levels. Nevertheless, the necessary physical proof has yet to be found to convince the skeptics. *wobble: to shake or move from side to side *tilt: to be in a sloping position   1 The word “ prevailed ” in the passage is  closest in meaning to Geologists have shown that for about 80 percent of the past 2.5 million years, ice-age conditions have  prevailed   on the Earth’s surface. During the past one million years, increased glacial conditions have run in cycles of  approximately 100,000 years. A ruled B existed C survived D triumphed     2 What can be inferred from paragraph  2 about the factors that contribute to  glaciation? → Many different factors may contribute to these increases  in glaciation at regular intervals throughout Earth’s more  geologically recent history. The three most prominent factors probably relate to the amount of sunlight that reaches the Earth. This varies over time for three main reasons. First, the planet wobbles as it spins, due to the pull of the sun and moon. Furthermore, the Earth tilts on its axis and the degree of tilt changes over time. Finally, the orbit of the Earth around the sun is elliptical and the length of the major axis of the ellipse changes over a period of about 100,000 years. A mathematician named Milutin Milankovitch discovered in the 1930s that the pattern of insolation, or sunlight, predicted by these eccentricities in the Earth’s movement matched the period of the last several eras of intense glaciation. A They affect the Earth’s spin. B They are geologically recent C Only three factors relate to levels  of sunlight. D Other factors than those relating to  the sunlight affect ice buildup Paragraph 2 is marked with an arrow [→].   3 The phrase “ these eccentricities ” in  the passage refers to all of the following  EXCEPT Many different factors may contribute to these increases  in glaciation at regular intervals throughout Earth’s more  geologically recent history. The three most prominent factors probably relate to the amount of sunlight that reaches the Earth. This varies over time for three main reasons. First, the planet wobbles as it spins, due to the pull of the sun and moon. Furthermore, the Earth tilts on its axis and the degree of tilt changes over time. Finally, the orbit of the Earth around the sun is elliptical and the length of the major axis of the ellipse changes over a period of about 100,000 years. A mathematician named Milutin Milankovitch discovered in the 1930s that the pattern of insolation, or sunlight, predicted by these eccentricities in the Earth’s movement matched the period of the last several eras of intense glaciation. A the various movements of the  Earth as it spins B the degree of change in the Earth’s  tilt over time C the pattern of insolation matching  the Earth’s movement D the changing distance to the sun  during the Earth’s elliptical orbit     4 Scientists accepted the Milankovitch theory even though [Refer to the full passage.] A the peaks of sunlight occurred at  intervals of 95,000 and 125,000  years B the peaks of insolation and intense  glaciation did not match C there were climate records of a  400,000-year cycle D there were microfossil deposits on  the sea floor     5 In paragraph 4, why does the author  suggest the image of a flat plane? →These and other problems with the Milankovitch cycles led some researchers to seek alternative explanations for the cyclic arrival of extended ice ages. In the 1990s, it was discovered that the orbital inclination of the Earth to the sun and planets could also be responsible for climate changes. If we imagine a flat plane with the sun in the center and the planets revolving around it, the Earth slowly moves in and out of the flat plane by a few degrees, repeating the cycle every 100,000 years. Two scientists, Muller and MacDonald, have proposed that it is this orbital inclination which is ultimately responsible for the periods of glaciation and warming. They argue that because of the oscillation, the Earth periodically travels through clouds of debris, in the form of dust and meteoroids. Such debris could reduce the amount of solar energy reaching the surface of our planet, thus plunging it into regular cold periods. A To help the reader visualize the positions and movements of the heavenly bodies B To demonstrate to the reader how the Earth orbits the sun C To support the argument that the orbital inclination increases tilting D To show how the Milankovitch theory doesn’t explain the cyclical changes in climate Paragraph 4 is marked with an arrow [ →].   6 The word “ it ” in the passage refers to These and other problems with the Milankovitch cycles led some researchers to seek alternative explanations for the cyclic arrival of extended ice ages. In the 1990s, it was discovered that the orbital inclination of the Earth to the sun and planets could also be responsible for climate changes. If we imagine a flat plane with the sun in the center and the planets revolving around it, the Earth slowly moves in and out of the flat plane by a few degrees, repeating the cycle every 100,000 years. Two scientists, Muller and MacDonald, have proposed that it is this orbital inclination which is ultimately responsible for the periods of glaciation and warming. They argue that because of the oscillation, the Earth periodically travels through clouds of debris, in the form of dust and meteoroids. Such debris could reduce the amount of solar energy reaching the surface of our planet, thus plunging it into regular cold periods. A such debris B solar energy C the surface D our planet     7 In paragraph 4, the author explains that → These and other problems with the Milankovitch cycles led some researchers to seek alternative explanations for the cyclic arrival of extended ice ages. In the 1990s, it was discovered that the orbital inclination of the Earth to the sun and planets could also be responsible for climate changes. If we imagine a flat plane with the sun in the center and the planets revolving around it, the Earth slowly moves in and out of the flat plane by a few degrees, repeating the cycle every 100,000 years. Two scientists, Muller and MacDonald, have proposed that it is this orbital inclination which is ultimately responsible for the periods of glaciation and warming. They argue that because of the oscillation, the Earth periodically travels through clouds of debris, in the form of dust and meteoroids. Such debris could reduce the amount of solar energy reaching the surface of our planet, thus plunging it into regular cold periods. A Milankovitch did not know about the orbital inclination of the Earth B glaciation occurs when the orbital inclination has entered a new cycle C the Earth always travels through clouds of debris after moving out of the plane by a few degrees D the amount of solar energy reaching the Earth’s surface causes the changes of temperature Paragraph 4 is marked with an arrow [ →].   8 What problem in the Milankovitch theory was mentioned as being explained by the Muller and MacDonald theory? [Refer to the full passage.] A The climate records obtained by studying microfossil deposits not matching his predicted cycle B The irregularities of the Earth’s movements through orbital inclinations not following any pattern C The Earth’s spin wobbling in relation to the Earth’s oscillating inclination D The peak in the ice ages occurring at intervals between 95,000 and 125,000 years instead of 400,000     9 The word “ persuaded ” in the passage is closest in meaning to However, many researchers in this field are not yet persuaded by the inclination hypothesis. The main problem is that the amount of dust that falls to the ground when the Earth travels through space debris is relatively small – not enough to produce radical climate changes. Volcanic eruptions, for example, release much greater amounts of ash and dust and have relatively little effect on climate. Supporters have countered that the by-products created by the dust as it vaporizes on entering the atmosphere cause subtle changes to the energy levels. Nevertheless, the necessary physical proof has yet to be found to convince the skeptics. A convinced B discouraged C affected D challenged     10 What problem is associated with the Muller and MacDonald theory? [Refer to the full passage.] A The amount of debris that is released from volcanoes is proportional to the amount of interstellar dust. B The amount of ash from volcanoes and space dust that vaporizes in the atmosphere is too small. C The amount of dust entering the atmosphere is less than the amount of ash and dust released by volcanoes. D The by-products created by vaporized space dust cause relevant changes to the energy levels.     11 Look at the four squares [ ▄ ] that indicate where the following sentence could be added to the passage   When the Earth is at its furthest from the sun, less sunlight reaches the surface.   Where would the sentence best fit?   Choose the letter of the square that shows where the sentence should be added.

ANSWER KEYS AND EXPLANATION