Reading Comprehension Home Exercise – 01, PASSAGE D

PASSAGE D

 

19.       The author states that the research described in the first paragraph was undertaken in order to

A.      Determine the age of an actual meteor stream

B.      Identify the various structural features of meteor streams

C.      Explore the nature of a particularly interesting meteor stream

D.      Test the hypothesis that meteor streams become broader as they age

20.        It can be inferred from the passage that which of the following would most probably be observed during the Earth’s passage through a meteor stream if the conventional theories were correct?

A.      Meteor activity would gradually increase to a single, intense peak, and then gradually decline.

B.      Meteor activity would be steady throughout the period of the meteor shower.

C.      Meteor activity would rise to a peak at the beginning and at the end of the meteor shower.

D.      Random bursts of very high meteor activity would be interspersed with periods of very little activity.

21.       According to the passage, why do the dust particles in a meteor stream eventually surround a comet’s original orbit?

A.      They are ejected by the comet at differing velocities.

B.      Their orbits are uncontrolled by planetary gravitational fields.

C.      They become part of the meteor at different times.

D.      Their velocity slows over time.

22.       The passage suggests that which of the following is a prediction concerning meteor streams that can be derived from both the conventional theories and the new computer – derived theory?

A.      Dust particles in a meteor stream will usually be distributed evenly throughout any cross section of the stream.

B.      The orbits of most meteor streams should cross the orbit of the Earth at some point and give rise to a meteor shower.

C.      Over time the distribution of dust in a meteor stream will usually become denser at the outside edges of the stream than at the centre.

D.      Meteor showers caused by older meteor streams should be, on average longer in duration than those caused by very young meteor streams.

23.       It can be inferred from the last paragraph of the passage that which of the following must be true of the Earth as it orbits the Sun?

A.      Most meteor streams it encounters are more than 2,000 years old.

B.      When passing through a meteor stream, it usually passes near to the stream’s centre.

C.      It crosses the Geminid meteor stream once every year.

D.      It usually takes over a day to cross the actual Geminid meteor stream.

24.       Which of the following is an assumption underlying the last sentence of the passage?

A.      In each of the years between 1970 and 1979, the Earth took exactly 19 hours to cross the Geminid meteor stream.

B.      The comet associated with the Geminid meteor stream has totally disintegrated.

C.      The Geminid meteor stream should continue to exist for at least 5, 000 years.

D.      The computer-model Geminid meteor stream provides an accurate representation of the development of the actual Geminid stream.

Answers and Explanations

19.       D    The reference needed to answer this question – Astronomers hypothesized that a meteor stream should broaden with time. A recent computer – modeling experiment tested this hypothesis. Thus, the research was conducted in order to test the hypothesis that meteor streams broaden with age. 

20.       A    If the conventional theories were true, it could be inferred that there would be one intense period of activity as the Earth passed through the dense centre of the meteor stream. The computer model showed instead there meteor stream resembled a thick-walled, hollow pipe. According to the computer model’s prediction. Earth would experience two periods of meteor activity as it passed through the meteor stream, one as it entered the “pipe” and one as it exited. Observation of the Geminid meteor shower shows just such a bifurcation. 

21.       A     The first paragraph describes the composition and behavior of meteor streams. The dust particles that make up the meteor stream are ejected from the comet at a –variety of velocities. 

Eventually, a shroud of dust surrounds the entire cometary orbit because of the differing velocities of these dust particles. 

22.       D    The hypothesis is that a meteor stream should broaden with time, this hypothesis is consistent with both conventional and computer –derived theories regarding the nature of the centre of the meteor stream. Thus, the broader the meteor stream is, the older it is. Meteor showers occur whenever Earth passes through a meteor stream. It can be inferred that if the meteor stream is older and broader. Earth will experience longer periods of meteor showers as it passes through this broad stream than it would if the meteor stream were younger and therefore less broad. 

23.       C     Read the last paragraph and compares it with the inferences given in the answer choice. Earth experiences meteor showers every time it passes through a meteor stream. The last paragraph identifies the Geminid meteor showers as occurring yearly. Therefore it is logical to infer that the Earth must pass through the Geminid meteor stream yearly. 

24.         D  The last sentence establishes the approximate date of the Geminid meteor stream. How is this date determined? The computer model shows that the Earth would cross the meteor stream in a little more than 24 hours if the stream were 5,000 years old. One decade’s data show that the Earth crossed the meteor stream in an average of 19 hours. The conclusion that the stream is about 3, 000 years old assumes that the computer model is accurate.