Section4-I-12
12. Impact craters caused by meteorites smashing into Earth have been found all around the globe, but they have been found in the greatest density in geologically stable regions. This relatively greater abundance of securely identified crater in geologically stable regions must be explained by the lower rates of destructive
geophysical processes in those regions.
The conclusion is properly drawn if which one of the following is assumed?
(A) A meteorite that strikes exactly the same spot as an earlier meteorite will obliterate all traces of the earlier impact.
(B) Rates of destructive geophysical processes within any given region vary markedly throughout geological time.
(C) The rate at which the Earth is struck by meteorites has greatly increased in geologically recent times.
(D) Actual meteorite impacts have been scattered fairly evenly over the Earth's surface in the course of Earth's geological history.
(E) The Earth's geologically stable regions have been studied more intensively by geologists than have its less stable regions.
answer my choice:B
15. M: It is almost impossible to find a person between the ages of 85 an 90 who primarily uses the left hand.
Q: Seventy to ninety years ago, however, children were published for using their left hands to eat or to write and were forced to use their right hands.
Q's response serves to counter any use by M of the evidence about 85 to 90 year olds in supports of which one of the following hypotheses?
(A) Being born right-handed confers a survival advantage.
(B) Societal attitudes toward handedness differ at different times.
(C) Forcing a person to switch from a preferred hand is harmless.
(D) Handedness is a product of both genetic predisposition and social pressures.
(E) Physical habits learned in school often persist in old age.
answer:A my choice: D
19. A tree's age can be determined by counting the annual growth rings in its trunk. Each ring represents one year, and the ring's thickness reveals the relative amount of rainfall that year. Archaeologists successfully used annual rings to determine the relative ages of ancient tombs at Pazyryk. Each tomb was constructed from freshly cut logs, and the tombs builders were constrained by tradition to use only logs from trees growing in the sacred Pazyryk Valley.
Which one of the following, if true, contributes most to an explanation of the archaeologists' success in using annual rings to establish the relative ages of the tombs at the Pazyryk site?
(A) The Pazyryk tombs were all robbed during ancient times, but breakage of the tombs seals allowed the seepage of water, which soon froze permanently, thereby preserving the tombs' remaining artifacts.
(B) The Pazyryk Valley, surrounded by extremely high mountains, has a distinctive yearly pattern of rainfall,and so trees growing in the Pazyryk Valley have annual rings that are quite distinct from trees growing in nearby valleys.
(C) Each log in the Pazyryk tombs has among its rings a distinctive sequence of twelve annual rings representing six drought years followed by three rainy years and three more drought years.
(D) The archaeologists determined that the youngest tree used in any of the tombs was 90 years old and that the oldest tree was 450 years old.
(E) All of the Pazyryk tombs contained cultural artifacts that can be dated to roughly 2300 years ago.
answer:C my choice:B
[此贴子已经被作者于2003-9-5 11:38:49编辑过]
作者: uclb5550 时间: 2003-9-5 16:26
12. Sorely on the basis of choice B, you cannot exclude the possibility that an extraordinary large number of meteorites unequally fell on a geological region that has a lower rate of destructive geophysical process. So, you cannot sure which reason finally contribute the present abundance of impact caters. From choice C, you can know that, initially, meteorites have been evenly scattered over earth's surface and thus have left generally an equal number of impact caters all over earth. Under this cricumstance, a lower rate of destructive geophysical process becomes the only reason for the fact that, there are quite a larger number of caters in some region while there are fewer in others.
15. This question actually exhibits the strict logical obsession in LSAT vividly. First, pay attention to the words " it is almost impossible". These words tell you that almost all of people mentioned in the article use right hand. Coupled with what the second person said, the conclusion seems inevitable that people's handedness is overwhelmingly influenced by social pressures. Therefore, genetic predisposition cannot be a contributing factor. PLease dont argue with me it sounds impossible in the actual situation. In here, we should deduct every conculsion only from the content of the article.
19. The key in this question is to find out the precise correlation between tree rings and tree age. Choice B only tells you that the pattern of tree rings in the P valley is disctinctive with that of trees in other valley. But it does not show you overtly that those tree rings can represent the age of tree. Choice C sets up such a correlation.作者: bigmouse 时间: 2003-9-5 19:20
谢谢解答！正在研究……！作者: uclb5550 时间: 2003-9-5 19:51
呵呵！ Please feel free to ask if you have any different opinion.作者: bigmouse 时间: 2003-9-5 21:48
my choice:B