OG48-14(又一難度頗高的科學類-太空題型)

[agk99]

Passage 14 科學類型文章

這一篇就真的辛苦了，但還是貼出來，大家一起想想辦法
八題錯四題

A meteor stream(一道流星) is composed of dust particles(微粒) that have been ejected from(從..噴出) a parent comet(慧星) at a variety of velocities(速度). These particles follow the same orbit as the parent comet, but due to their differing velocities they slowly gain on or fall behind the disintegrating(碎裂) comet until a shroud(遮蔽物) of dust surrounds the entire cometary(慧星的) orbit. Astronomers(天文學家) have hypothesized that a meteor stream should broaden with time as the dust particles’ individual orbits are perturbed(被動語態，不安) by planetary(行星的) gravitational(地心引力的) fields. A recent (訊號字)computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected 5,000-year period on the positions of a group of hypothetical dust particles. In the model, the particles were randomly distributed throughout(各方面) a computer simulation(模仿) of the orbit of an actual meteor stream, the Geminid. The researcher found, as expected, that the computer-model stream broadened with time. Conventional theories, however, predicted that the distribution of particles would be increasingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe(中空的管子).
第一段只看得比較確定是最後一句話：傳統理論以為流星的微粒是向中間集中，沒想到由電腦測試的結果，流星微粒竟是向四周分散，向管子一樣的中空型式。

Whenever the Earth passes through a meteor stream, a meteor shower occurs. Moving at a little over 1,500,000 miles per day around its orbit, the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed, one as the Earth entered the thick-walled(粗又厚) “pipe” and one as it exited. There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts(爆炸) of activity would vary from one year to the next.

Has the predicted twin-peaked activity been observed for the actual yearly GEminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation(分叉), a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.

80. The primary focus of the passage is on which of the following?
(A) Comparing two scientific theories and contrasting the predictions that each would make concerning a natural phenomenon
(B) Describing a new theoretical model and noting that it explains the nature of observations made of a particular natural phenomenon
(C) Evaluating the results of a particular scientific experiment and suggesting further areas for research
(D) Explaining how two different natural phenomena are related and demonstrating a way to measure them
(E) Analyzing recent data derived from observations of an actual phenomenon and constructing a model to explain the data

81. According to the passage, which of the following is an accurate statement concerning meteor streams?
(A) Meteor streams and comets start out with smiliar orbits, but only those of meteor streams are perturbed by planetary gravittion.
(B) Meteor streams grow as dust particles are attracted by the gravitational fields of comets.
(C) Meteor streams are composed of dust particles derived from comets.
(D) Comets may be composed of several kinds of materials, while meteor streams consitst only of large dust particles.
(E) Once formed, meteor streams hasten the further disintegration of comets.

*82. 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
(E) show that a computer model could help in explaining actual astronomical data
做錯，答案給D

*83. 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 mentioned in line 18 were(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.
(E) In years in which the Earth passed through only the outer areas of a meteor stream, meteor activity would be absent.
猜C，答案給A

*84. According to the passage, why do the dust particles in a meteor stream eventually (最後) 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 stream at different times.
(D) Their velocity slows over time.
(E) Their ejection velocity is slower than that of the comet.
答案給A

*85. The passage suggests that which of the following is a prediction concerning meteor streams that can be derived from both the conventional theories mentioned in line 18 and the new computer-derived theory?(A) Dust particles in a meteor stream will usually be distributed evenly throughout any cross section of the steam.
(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 center.
(D) Meteor showers caused by older by older meteor streams should be, on average, longer in duration than those caused by very young meteor streams.
(E) The individual dust particles in older meteor streams should be, on average, smaller than those that compose younger meteor streams.
答案是D

*86. 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 center.
(C) It crosses the Geminid meteor stream once every year.
(D) It usually takes over a day to cross the actual Geminid meteor stream.
(E) It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.
我是BE選一個，但答案是C

87. 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 Geminid meteor stream has not broadened as rapidly as the conventional theories would have predicted.
(E) The computer-model Geminid meteor stream provides an accurate representation of the development of the actual Geminid stream.

[Grace]

Passage 14
A meteor stream is composed of dust particles that have been ejected from a parent comet at a variety of velocities (速度). These particles follow the same orbit as the parent comet, but due to their differeing velocities they slowly gain on or fall behind the disintegrating (分解) comet until a shroud(遮蔽物) of dust surrounds the entire cometary orbit. Astronomers have hypothesized that a meteor stream should broaden with time as the dust particles’ individual orbits are perturbed(干擾) by planetary gravitational fields. A recent computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected (=expected) 5,000-year period on the positions of a group of hypothetical dust particles. In the model, the particles were randomly distributed throughout a computer simulation (模擬) of the orbit of an actual meteor stream, the Geminid. The researcher found, as expected, that the computer-model stream broadened with time. Coventional theories, however, predicted that the distribution of particles would be increaingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe.

總結: 作者先提出新理論 particle randomly distributed, 與conventional theory對比--- particle increasingly dense toward the center of a meteor stream.

作者態度用詞 Surpringly, should, due to, as expected, however
Choice of word Recent, hypothesized, perturbed, disintegrating, projected, randomly distributed, simulation, conventional, predict, increasingly, dense, thicked-walled
對比 Randomly distributed VS increasingly dense toward the center
因果 These particles follow the same orbit as the parent comet, but due to their differeing velocities they slowly gain on or fall behind the disintegrating comet until a shroud of dust surrounds the entire cometary orbit.
假設 Astronomers have hypothesized that a meteor stream should broaden with time as the dust particles’ individual orbits are perturbed(干擾) by planetary gravitational fields.
文章development
1.analysize
2.problem-solution
3.approach
4.data
5.explain
6identify
7.define
8.compare/contrast
9.refute
10.new idea Compare & contrast
Attitude
26. critical
27. questioning
28. objective (neutrality)\subjecitce
29. enthusiastic
30. approval\disapproval Critical


Whenever the Earth passes through a meteor stream, a meteor shower occurs. Moving at a little over 1,500,000 miles per day around its orbit, the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed, one as the Earth entered the thick-walled “pipe” and one as it exited. There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts of activity would vary from one year to the next.

總結:

作者態度用詞 Just, if, no reason why, should always, so, would,
Choice of word exact, on average, “pipe”, vary
對比
因果 There is no reason why the Earth should always pass through the stream’s exact center, so the time interval between the two bursts of activity would vary from one year to the next.

假設 the Earth would take, on average, just over a day to cross the hollow, computer-model Geminid stream if the stream were 5,000 years old.
文章development
1.analysize
2.problem-solution
3.approach
4.data
5.explain
6identify
7.define
8.compare/contrast
9.refute
10.new idea explain
Attitude
31. critical
32. questioning
33. objective (neutrality)\subjecitce
34. enthusiastic
35. approval\disapproval Neutral


Has the predicted twin-peaked activity been observed for the actual yearly GEminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation (分叉), a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.

作者態度用詞 Show just such, suggest, actual
Choice of word bifurcation
對比 Bifurcation: 19 hours (1,200,000 miles) vs 第二段 a day (1500,000 miles)
因果 Time interval Age
假設
文章development
1.analysize
2.problem-solution
3.approach
4.data
5.explain
6identify
7.define
8.compare/contrast
9.refute
10.new idea explain
Attitude
36. critical
37. questioning
38. objective (neutrality)\subjecitce
39. enthusiastic
40. approval\disapproval neutral

80. The primary focus of the passage is on which of the following?
(A) Comparing two scientific theories and contrasting the predictions that each would make concerning a natural phenomenon
(B) Describing a new theoretical model and noting that it explains the nature of observations made of a particular natural phenomenon
(C) Evaluating the results of a particular scientific experiment and suggesting further areas for research
(D) Explaining how two different natural phenomena are related and demonstrating a way to measure them
(E) Analyzing recent data derived from observations of an actual phenomenon and constructing a model to explain the data

81. According to the passage, which of the following is an accurate statement concerning meteor streams?
(A) Meteor streams and comets start out with smiliar orbits, but only those of meteor streams are perturbed by planetary gravittion. (Line 8 dust particles’ individual orbits are perturbed)
(B) Meteor streams grow as dust particles are attracted by the gravitational fields of comets.
(C) Meteor streams are composed of dust particles derived from(=ejected from) comets.( Line 2)
(D) Comets may be composed of several kinds of materials, while meteor streams consitst only of large dust particles.
(E) Once formed, meteor streams hasten(=accerlerate) the further disintegration of comets. (slowly gain on or fall behind the disintegration)

82. 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
(E) show that a computer model could help in explaining actual astronomical data

83. 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 mentioned in line 18 were correct?
(A) Meteor activity would gradually increase to a single, intense peak, and then gradually decline.(conventional theory--dense )
(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. (new theory--bifurcation)
(D) Random bursts of very high meteor activity would be interspersed with periods of very little activity.
(E) In years in which the Earth passed through only the outer areas of a meteor stream, meteor activity would be absent.

84. According to the passage, why do the dust particles in a meteor stream eventually surround a comet’s orginla orbit?
(A) They are ejected by the comet at differing velocities.
(B) Their orbits are uncontrolled by planetary gravitational fields. (perturbed)
(C) They become part of the meteor stream at different times.
(D) Their velocity slows over time.
(E) Their ejection velocity is slower than that of the comet.

85. The passage suggests that which of the following is a prediction concerning meteor streams that can be derived from both the conventional theories mentioned in line 18 and the new computer-derived theory?
(A) Dust particles in a meteor stream will usually be distributed evenly throughout any cross section of the steam.
(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 center.==> dense toward the center
(D) Meteor showers caused by older by older meteor streams should be, on average, longer in duration than those caused by very young meteor streams. (Line 7 “have hypothesized”—conventional theory, Line 10 “recent”—new theory)
(E) The individual dust particles in older meteor streams should be, on average, smaller than those that compose younger meteor streams.

86. 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 center.
(C) It crosses the Geminid meteor stream once every year. (Line 35“yearly”+Line23 )
(D) It usually takes over a day to cross the actual Geminid meteor stream. (Line 28 5000 years old; Line 41 3000years old)
(E) It accounts of msot of the gravitaitonal perturbation affecting the Geminid meteor stream.

87. 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 Geminid meteor stream has not broadended as rapidly as the conventiona ltheories would have predicted.
(E) The computer-model Geminid meteor stream provides an accurate representation of the development of the actual Geminid stream.

作者態度用詞
Choice of word 81
對比
因果 84, 85
假設 83 87
文章development
1.analysize
2.problem-solution
3.approach
4.data
5.explain
6identify
7.define
8.compare/contrast
9.refute
10.new idea 82
Attitude
41. critical
42. questioning
43. objective (neutrality)\subjecitce
44. enthusiastic
45. approval\disapproval

[soami]

懇請大衛飄一下這篇吧，這篇文章讓我看的似懂非懂，

天文類的文章我都看的霧殺殺。

[agk99]

說一下你做題的困擾好了
這一篇大衛前幾天才和我做過，任何具體問題我可以代表先回答
他老兄恐怕還要再過一小時的生日呢

[davidlee0222]

老大說的對
上週六應該錄音的

[soami]

86. 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 center.
(C) It crosses the Geminid meteor stream once every year.
(D) It usually takes over a day to cross the actual Geminid meteor stream.
(E) It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.

我對這題很感覺很火大...og給的解釋是因為選項c有every year，就可以推得地球繞著太陽轉的事實。

[soami]

A meteor stream is composed of dust particles流星群由塵粒子組成 that have been ejected from a parent comet at a variety of velocities.這些塵粒子由母彗星以不同速率彈出來 These particles follow the same orbit as the parent comet, 塵粒子跟母星的保持同樣的軌道 but due to their differing velocities 速率不同 they slowly gain on or fall behind the disintegrating comet 塵粒子會增加或減少 until a shroud of dust surrounds the entire cometary orbit. 這邊有點抽象，不過應該不是大方向
Astronomers have hypothesized that a meteor stream should broaden with time 科學家預期 a meteor stram 會隨著時間擴大 as the dust particles’ individual orbits are perturbed by planetary gravitational fields.因為行星引力場的關係 A recent computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected 5,000-year period on the positions of a group of hypothetical dust particles. 最近電腦實驗這個理論，透過追蹤行星引力的引響
In the model, the particles were randomly distributed throughout a computer simulation of the orbit of an actual meteor stream, the Geminid. 實驗當中，塵粒子隨機分佈在一個實際存在雙子星群軌道的電腦模擬物，這句不好翻，我是直譯下來。
The researcher found, as expected, that the computer-model stream broadened with time. 一如預期，stream隨著時間擴大

Conventional theories, however, predicted that the distribution of particles would be increasingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe.
第一段只看得比較確定是最後一句話：傳統理論以為流星的微粒是向中間集中，沒想到由電腦測試的結果，流星 微粒竟是向四周分散，向管子一樣的中空型式。

Whenever the Earth passes through a meteor stream, a meteor shower occurs.地球穿越一個流星群的時候為會發生一場流星雨 Moving at a little over 1,500,000 miles per day around its orbit,修飾地球 the Earth would take, on average, just over a day to cross the hollow,穿過中空洞要一天 computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed,二個時間可以觀察到流星雨的高峰 one as the Earth entered the thick-walled “pipe” and one as it exited.地球進入和離開中空管的時候
There is no reason why the Earth should always pass through the stream’s exact center,這句可以理解，但是下一句我搞不懂 so the time interval between the two bursts of activity would vary from one year to the next. 介於二個流星雨高峰活動的時間間隔，可能每年都會不太一樣????

第二段看起來跟第一段沒什麼關係，殺出來介紹流星雨。

Has the predicted twin-peaked activity been observed for the actual yearly GEminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation(分叉), a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.

這段跟第一段也看不出來有什麼關聯，不知道這麼文章到底想要表達什麼?
從一個新發現跟傳統理論不同，然後一直跳掉x@#$%$....

[yongzhou]

A meteor stream is composed of dust particles流星群由塵粒子組成 that have been ejected from a parent comet at a variety of velocities.這些塵粒子由母彗星以不同速率彈出來 These particles follow the same orbit as the parent comet, 塵粒子跟母星的保持同樣的軌道 but due to their differing velocities 速率不同 they slowly gain on or fall behind the disintegrating comet 塵粒子會增加或減少 不是數目,是速度--跑前或落後until a shroud of dust surrounds the entire cometary orbit. 這邊有點抽象，不過應該不是大方向
Astronomers have hypothesized that a meteor stream should broaden with time 科學家預期 a meteor stram 會隨著時間擴大 as the dust particles’ individual orbits are perturbed by planetary gravitational fields.因為行星引力場的關係 A recent computer-modeling experiment tested this hypothesis by tracking the influence of planetary gravitation over a projected 5,000-year period on the positions of a group of hypothetical dust particles. 最近電腦實驗這個理論，透過追蹤行星引力的引響
In the model, the particles were randomly distributed throughout a computer simulation of the orbit of an actual meteor stream, the Geminid. 實驗當中電腦模擬實存在的雙子星群軌道，塵粒子起先隨機分散，這句不好翻，我是直譯下來。
The researcher found, as expected, that the computer-model stream broadened with time. 一如預期，stream隨著時間擴大

Conventional theories, however, predicted that the distribution of particles would be increasingly dense toward the center of a meteor stream. Surprisingly, the computer-model meteor stream gradually came to resemble a thick-walled, hollow pipe.
第一段只看得比較確定是最後一句話：傳統理論以為流星的微粒是向中間集中，沒想到由電腦測試的結果，流星 微粒竟是向四周分散，向管子一樣的中空型式。

Whenever the Earth passes through a meteor stream, a meteor shower occurs.地球穿越一個流星群的時候為會發生一場流星雨 Moving at a little over 1,500,000 miles per day around its orbit,修飾地球 the Earth would take, on average, just over a day to cross the hollow,穿過中空洞要一天 computer-model Geminid stream if the stream were 5,000 years old. Two brief periods of peak meteor activity during the shower would be observed,二個時間可以觀察到流星雨的高峰 one as the Earth entered the thick-walled “pipe” and one as it exited.地球進入和離開中空管的時候
There is no reason why the Earth should always pass through the stream’s exact center,這句可以理解，但是下一句我搞不懂 so the time interval between the two bursts of activity would vary from one year to the next. 介於二個流星雨高峰活動的時間間隔，可能每年都會不太一樣????(有時從靠近管子中央一點,有時邊邊切過,時間間隔因此不同)

第二段看起來跟第一段沒什麼關係，殺出來介紹流星雨。

Has the predicted twin-peaked activity been observed for the actual yearly GEminid meteor shower? The Geminid data between 1970 and 1979 show just such a bifurcation(分叉), a secondary burst of meteor activity being clearly visible at an average of 19 hours (1,200,000 miles) after the first burst. The time intervals between the bursts suggest the actual Geminid stream is about 3,000 years old.

這段跟第一段也看不出來有什麼關聯，不知道這麼文章到底想要表達什麼?
從一個新發現跟傳統理論不同，然後一直跳掉x@#$%$....

soami, 應該是蠻有關聯的喔,第一段---背景介紹, 第二段---電腦模擬, 第三段--- 那實際天文觀察是否吻合? Yes, 每年都看到這樣的雙峰流星雨

[yongzhou]

86. 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 center.
(C) It crosses the Geminid meteor stream once every year.
(D) It usually takes over a day to cross the actual Geminid meteor stream.
(E) It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.

我對這題很感覺很火大...og給的解釋是因為選項c有every year，就可以推得地球繞著太陽轉的事實。

是說每年通過Geminid慧星群流

[copycat]

我也覺得很困擾..第三段開頭是一個問句?我實在找不出哪裡可以提供yes的資訊..有誰可以救救我..(頭昏)

[lunar916]

我也覺得很困擾..第三段開頭是一個問句?我實在找不出哪裡可以提供yes的資訊..有誰可以救救我..(頭昏)

下一句就是啦
Q: Has the predicted twin-peaked activity been observed for the actual yearly GEminid meteor shower?
A: The Geminid data between 1970 and 1979 show just such a bifurcation

Q: 預估的雙峰是否有在GEminid meteor shower中見到過?
A: 1970-1979 的Geminid 資料有顯示雙峰

文章寫了一大串只是在說computer model顯示的雙峰theory有被Geminid証實

[faithful]

86. 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 center.
(C) It crosses the Geminid meteor stream once every year.
(D) It usually takes over a day to cross the actual Geminid meteor stream.
(E) It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.

我對這題很感覺很火大...og給的解釋是因為選項c有every year，就可以推得地球繞著太陽轉的事實。

是說每年通過Geminid慧星群流

按照OG詳解及個人淺見，提出來供大家參考。如有錯誤，請不吝指正，畢竟在下今年9月也要上場。
(A) 文中沒提及，無關。不選。
(B) 按照文章31-32行，應該是"exact center"，不僅near。不選。
(C) 文章35-36行有提及，是否有實際觀察到每年發生的流行雨雙峰現象？
答案在後面，結果是肯定的。這也推論出地球每年都有經過Geminid，因為地球每年都會繞著太陽運行。正確答案。
(D) 根據本文無法得出此結論，因為文章25-28行說，需要超過一天的時間；然而，文章38-42行卻說平均是19小時。不選。
(E) 文中只有舉出，星球力場會干擾塵粒之運行，完全沒有說地球的力場是否會有較大的影響。不選。

[davidslin]

[quote="faithful"][quote="yongzhou"][quote="soami"]86. 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 center.
(C) It crosses the Geminid meteor stream once every year.
(D) It usually takes over a day to cross the actual Geminid meteor stream.
(E) It accounts of most of the gravitational perturbation affecting the Geminid meteor stream.


按照OG詳解及個人淺見，提出來供大家參考。如有錯誤，請不吝指正，畢竟在下今年9月也要上場。
(A) 文中沒提及，無關。不選。
(B) 按照文章31-32行，應該是"exact center"，不僅near。不選。

There is no reason why the Earth should always pass through the stream’s exact center,so the time interval between the two bursts of activity would vary from one year to the next.
我覺得這一句應該是說[沒有理由可以證實地球總是通過流星群的中心,所以兩次高峰的間隔每年都不同]
所以B不選的原因應該是地球並非通常都通過流星群的中心吧?

[greenfox]

我照自己對文章的理解,對86題做出以下的解釋,若是有誤請不吝指正
A.文章未提到此訊息
B.我贊同上一篇的說法,另我自己的理解是-天體的運行軌道通常是橢圓形,故地球從圓心穿過所花的時間自然不同於從弧穿過的時間
D.文章第25~28行提出"該數學模型模擬地球以每天約1500.000miles的速率通過5000年老的Geminid stream要花上約一天的時間"，又在文章第39~42行提到"實際在1970&1979觀察到地球以每天1200,000miles的速率通過Geminid stream要花上19小時,故可推算其年齡為3000年==>故可得知D是錯的
E.最後一段並未提供相關訊息可以符合選項所說的因果關係

至於C我自己後來說服自己的方法是
"Has the predicted twin-peaked activity been observed for the actual yearly Geminid meter shower?"==>故可得知地球每年都會通過Geminid stream

[jmyang]

我照自己對文章的理解,對86題做出以下的解釋,若是有誤請不吝指正
A.文章未提到此訊息
B.我贊同上一篇的說法,另我自己的理解是-天體的運行軌道通常是橢圓形,故地球從圓心穿過所花的時間自然不同於從弧穿過的時間
D.文章第25~28行提出"該數學模型模擬地球以每天約1500.000miles的速率通過5000年老的Geminid stream要花上約一天的時間"，又在文章第39~42行提到"實際在1970&1979觀察到地球以每天1200,000miles的速率通過Geminid stream要花上19小時,故可推算其年齡為3000年==>故可得知D是錯的
E.最後一段並未提供相關訊息可以符合選項所說的因果關係

至於C我自己後來說服自己的方法是
"Has the predicted twin-peaked activity been observed for the actual yearly Geminid meter shower?"==>故可得知地球每年都會通過Geminid stream

C. 理論上而言 Earth 可以一年通過同一個comet 軌道兩次：當 comet 接近 sun 的時候一次，遠離 sun 的時候一次。原文�並未排除這個可能，就說 (C) 的選項: once a year 是對的，實在有點牽強

D. 原文�也說 Earth 不一定會通過 Pipe 的中心點，所以就算是 5,000 year-old pipe 好了，不通過中心點的話，截徑路線就會對時間長短造成影響，19 hrs 並不代表就一定是 3,000 year-old。不過如此推論 D 還是錯的就是了。