P1: Two major theories that explain the lunar craters: (1) impact of meteorites and (2) volcanic activity. It then goes ahead to explain theory (1) in detail.
P2: Explains a shortcoming of theory (1) -
"The craters are smoother than expected" - and then goes on to suggest that this shortcoming could be avoided -
"unless there is some other mechanism"P3: Explains the "mechanism" mentioned in P2 thereby undermining the shortcoming of theory (1)
P4: The author shares his views by stating that the mechanism is flawed.
Note: The author DOES NOT undermind the Theory. He simply rejects the mechanism that was explaining a possible shortcoming of theory (1)
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1. According to the passage, one hypothesis proposed to explain the smoothness of the floors of large craters argues that the smoothness is a result of the"One mechanism that has been suggested is that those meteorites that formed the craters fell on the lunar surface when the Moon was in a semiplastic condition or, if they fell after the lunar crust had solidified,
that the impact itself would liquefy the surface rock sufficiently to force it to flow rather like lava."(A) disintegration of meteorites
(B) liquefying of surface rock -
CORRECT(C) numerous impacts of meteorites
(D) polar concentration of craters
(E) frictional burning of matter
Correct Answer: (B)------------------------------------------------------------------------------------------------------------------------------------------------
2. Which of the following statements about the meteorite impact theory is most clearly supported by the information in the passage?Quote:
(A) It is more acceptable to scientists than is the volcanism theory.
Incorrect "
There are two main theories concerning the origin of the lunar craters: one is that they were formed by the impact of meteorites, the other that they are due to some type of volcanic activity." The passage clear mentions that both the theories are the major ones. There is no preference between the two
Quote:
(B) It is able to explain some observed features of the Moon’s surface.
HOLD I don't have any reason to eliminate this choice. So I will keep this on hold and then consider this one.
(C) It is one of several theories all of which seem equally tenable to scientists.
Incorrect As mentioned in (B) There are only two theories that have got the majority of the attention
Quote:
(D) Its importance is primarily historical.
Incorrect Nowhere stated in the passage
Quote:
(E) It has been abandoned by most scientists.
Incorrect As mentioned in (B) This is one of the two major theories that is considered as a possible explanation
Looking at (C) I believe it is the correct answer. Why? because P1 talks about the "impact of meteorite". It further states some details that could explain the reason for the presence of craters. "the large majority of the craters were formed during the early stages of the Moon’s development when,
as seems possible, the number of meteoritic bodies moving in orbits similar to that of the Earth-Moon system was quite large.
Correct Answer: (C)------------------------------------------------------------------------------------------------------------------------------------------------
3. The passage states that, in contrast to meteorites that enter the Earth’s atmosphere, meteorites striking the Moon are(A) likely to be almost entirely burned up
(B) likely to fall close together
(C) likely to liquefy immediately
(D) able to create craters of widely varying diameters
(E) able to hit the surface at greater speeds -
Correct - Since the Moon, unlike the Earth, possesses no atmosphere, "
such bodies would reach the lunar surface at a higher velocity than they would reach Earth."
Correct Answer: (E)------------------------------------------------------------------------------------------------------------------------------------------------
4. The author suggests that the theory that has been presented to explain the existence of central mountain peaks in some craters is based on(A) the author's own observation of the behavior of lunar rock
(B) inadequate evaluations of the material structure of the lunar crust -
Correct - This is the essence of P4 "There is, unfortunately,
one very serious objection to this idea."
(C) inference from an apparently similar situation
(D) conjectures with which the author agrees
(E) information that has become outdated
Correct Answer: (A)------------------------------------------------------------------------------------------------------------------------------------------------
5. The author considers an explanation for the formation of very large lunar craters and then evaluates the explanation as
(A) confirmed by the characteristics of meteorites as they travel through space
(B) supported by observations concerning the liquefying of rocks
(C) incompatible, without further additions, with evidence of the smoothness of crater floors -
Correct -
For this simply check the summary of the passage. P2 explains a shortcoming of the theory. P3 explains a mechanism that undermines this shortcoming. P4 rejects this shortcoming. Choice (C) is a pretty cool summary of P1 P2 and P3(D) improbable because of a disparity with the known causes of analogous formations on Earth
(E) inconsistent, if unmodified, with the facts about the distribution of the large lunar craters
Correct Answer: (C)------------------------------------------------------------------------------------------------------------------------------------------------
6. It can be inferred from the passage that unevenness in the floors of craters should have resulted from the fact that(A) the meteorites that formed the craters had different masses of impact velocities ;
(B) the meteorites that formed the craters were all traveling at the same speed
(C) the meteorites that formed the craters all reached the Moon’s fur face at the same time -
Correct - "If we are to explain the very large craters on the assumption that several meteorites fell close together (in space,
although not necessarily in time) this would imply that such craters should have uneven floors"
(D) when the meteorites struck the Moon, its surface was in a semiplastic condition
(E) when the meteorites struck the Moon, its surface was already uneven
Correct Answer: (C)Sorry but I was on a time crunch. Tried to be as detailed as possible. I hope this helps