In July of 1994, an astounding series of events took place. The world anxiously watched as, every few hours, a hurtling chunk of comet plunged into the atmosphere of Jupiter. All of the twenty-odd fragments, collectively called comet Shoemaker-Levy 9 after its discoverers, were once part of the same object, now dismembered and strung out along the same orbit. This cometary train, glistening like a string of pearls, had been first glimpsed only a few months before its fateful impact with Jupiter, and rather quickly scientists had predicted that the fragments were on a collision course with the giant planet. The impact caused an explosion clearly visible from Earth, a bright flaming fire that quickly expanded as each icy mass incinerated itself. When each fragment slammed at 60 kilometers per second into the dense atmosphere, its immense kinetic energy was transformed into heat, producing a superheated fireball that was ejected back through the tunnel the fragment had made a few seconds earlier. The residues from these explosions left huge black marks on the face of Jupiter, some of which have stretched out to form dark ribbons.

　　Although this impact event was of considerable scientific import, it especially piqued public curiosity and interest. Photographs of each collision made the evening television newscast and were posted on the Internet. This was possibly the most open scientific endeavor in history. The face of the largest planet in the solar system was changed before our very eyes. And for the very first time, most of humanity came to fully appreciate the fact that we ourselves live on a similar target, a world subject to catastrophe by random assaults from celestial bodies. That realization was a surprise to many, but it should not have been. One of the great truths revealed by the last few decades of planetary exploration is that collisions between bodies of all sizes are relatively commonplace, at least in geologic terms, and were even more frequent in the early solar system.

　　1. The passage mentions which of the following with respect to the fragments of comet Shoemaker-Levy 9?

　　(A) They were once combine in a larger body.

　　(B) Some of them burned up before entering the atmosphere of Jupiter.

　　(C) Some of them are still orbiting Jupiter.

　　(D) They have an unusual orbit.

　　2. The word "collectively" in line 3 is closest in meaning to

　　(A) respectively

　　(B) popularly

　　(C) also

　　(D) together

　　3. The author compares the fragments of comet Shoemaker-Levy 9 to all of the following EXCEPT

　　(A) a dismembered body

　　(B) a train

　　(C) a pearl necklace

　　(D) a giant planet

　　4. Before comet Shoemaker-Levy 9 hit Jupiter in July 1994, scientists

　　(A) had been unaware of its existence

　　(B) had been tracking it for only a few months

　　(C) had observed its breakup into twenty-odd fragments

　　(D) had decided it would not collide with the planet

　　5. Before the comet fragments entered the atmosphere of Jupiter, they were most likely

　　(A) invisible

　　(B) black

　　(C) frozen

　　(D) exploding

　　6. Superheated fireballs were produced as soon as the fragments of comet Shoemaker- Levy 9

　　(A) hit the surface of Jupiter

　　(B) were pulled into Jupiter's orbit

　　(C) were ejected back through the tunnel

　　(D) entered the atmosphere of Jupiter

　　7. The phrase "incinerated把。。。烧成灰 itself" in line 9 is closest in meaning to

　　(A) burned up

　　(B) broke into smaller pieces

　　(C) increased its speed

　　(D) grew in size

　　8. Which of the following is mentioned as evidence of the explosions that is still visible on Jupiter?

　　(A) fireballs

　　(B) ice masses

　　(C) black marks

　　(D) tunnels

　　9. Paragraph 2 discusses the impact of the comet Shoemaker-Levy 9 primarily in terms of

　　(A) its importance as an event of great scientific significance

　　(B) its effect on public awareness of the possibility of damage to Earth

　　(C) the changes it made to the surface of Jupiter

　　(D) the effect it had on television broadcasting

　　10. The "target" in line 20 most probably referred to

　　(A) Earth

　　(B) Jupiter

　　(C) the solar system

　　(D) a comet

　　ADDBC DACBA

　　词汇补充：

　　cacia 金合花

　　accordion 手风琴

　　acquamarine 海蓝宝石

　　acre 英亩

　　acronym首字母缩拼词

　　acute 敏锐的

　　adobe 土墙

　　adorn 装饰

　　adrenaline 肾上腺素

　　affiliate 使隶属于

　　affinity 密切关系

　　afloat 漂浮着

　　aide 副官

　　airborne 在空中

　　alchemist 炼丹家

　　aldosterone 醛固酮

　　alga 水藻

　　allegory 寓言

　　all-star 由明星演员组成的

　　allusive 含暗示的;含典故的

　　aloof 远离的;孤零的

　　aluminum 铝

　　alumni 男校友

　　amateur 外行的