passage 106 星系吞噬
★★★☆
太空并非一片死寂，从天文研究所发现的冰山一角来看，它处处充满生机。天体竟然和人一样也有出生、衰老和死亡；有的小天体会在行星之间沿着“星际高速公路”漫游；两个相互绕转的黑洞最终可能撞出引力波；星系之间也会“弱肉强食”，一个吞噬另一个。当未知世界的面纱被科学发现一点点掀开，事实常常与我们的预想和假设迥异。所以在认识和了解之前，不如多一点敬畏，少一点妄下结论。正如苏格拉底所言：除了自己的无知，我一无所知。
——新浪科技
看题：
1. The primary purpose of the passage is to 主旨目的考论证结构
2. The “large clumps and streamers of stars” represent observational data cited by the author of the passage as an example of 结构考信息关系
3. According to the passage, a true double nucleus may be produced by the 直接信息，读到就做
文章分析：
①Instances of “galactic cannibalism”—mergers in which large galaxies completely consume smaller ones—may be fairly common. ②Tidal forces produced by the Milky Way’s powerful gravity, for example, appear to be dismantling and engulfing a dwarf galaxy in the constellation Sagittarius, producing large clumps and streamers of stars connecting the two galaxies. ③Astronomers have also observed two dense clusters of stars and gas at the heart of the Andromeda galaxy, an apparent “double nucleus” that may contain the remnant of a cannibalized dwarf galaxy. ④But this twin-lobed appearance could also be created by two parts of a single nucleus bisected by a lane of dust. ⑤Scientists believe that only about 25 percent of such apparent double nuclei actually represent galactic cannibalism. ⑥Many of the rest result from the illusion of proximity that occurs when objects at different distances appear along the same line of sight; others consist of debris from galactic “collisions,” in which one galaxy has passed through another without merging, causing waves of new star formation.
①事实，介绍星系吞噬
②举例
③另一个例子
④但也可能是另一种解释
⑤科学家观点认为只有25%是真的
⑥其他的可能产生原因
①
↓
② + ③ ↔ ④
↓
⑤
↓
⑥
1. The primary purpose of the passage is to 主旨目的题
A. suggest that galactic cannibalism occurs more commonly than previously supposed 没有证据
B. indicate the difficulty of determining whether galactic cannibalism actually occurs
C. demonstrate flaws in the evidence used to prove that galactic cannibalism actually occurs 干扰项，原文可以认为是现象解释。没有证据
D. outline the process by which galactic cannibalism takes place 说明文
E. present evidence that galactic cannibalism has occurred in a given instance 没有证据
2. The “large clumps and streamers of stars” represent observational data cited by the author of the passage as an example of 结构题
A. the star configuration typical of a dwarf galaxy 没有证据
B. galactic cannibalism that is still in progress 除了对应给上句的fairy common举例, 也对应当句的dismantling and engulfing
C. waves of new star formation resulting from a galactic collision 没有证据/无关，对应⑥不在答题区间
D. debris from a galactic collision coalescing into a double nucleus 同上
E. material connecting the two nuclei of a galaxy formed by galactic cannibalism 没有证据
3. According to the passage, a true double nucleus may be produced by the
A. collision of two dwarf galaxies 没有证据
B. incorporation of a dwarf galaxy into a larger galaxy对应②
C. merging of two galaxies of approximately equal size 没有证据
D. separation of a single nucleus into two parts by a lane of dust 对应④，相反
E. waves of new star formation resulting from an instance of galactic cannibalism 对应⑥，相反
背景拓展：
galactic cannibalism 星系吞噬
Interacting galaxies (colliding galaxies) are galaxies whose gravitational fields result in a disturbance of one another. An example of a minor interaction is a satellite galaxy's disturbing the primary galaxy's spiral arms. An example of a major interaction is a galactic collision, which may lead to a galaxy merger.
tidal force 潮汐力
Sagittarius (constellation) 人马星座
Sagittarius is one of the constellations of the zodiac. It is one of the 48 constellations listed by the 2nd-century astronomer Ptolemy and remains one of the 88 modern constellations. Its name is Latin for the archer, and its symbol is (Unicode ♐), a stylized arrow. Sagittarius is commonly represented as a centaur pulling back a bow. It lies between Scorpius and Ophiuchus to the west and Capricornus and Microscopium to the east.
The center of the Milky Way lies in the westernmost part of Sagittarius.
