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Passage One

     Unidentified Flying Object (UFO), any object or light, reportedly sighted in the sky, that cannot be immediately explained by the observer. Sightings of unusual aerial phenomena date back to ancient times, but UFOs (sometimes called flying saucers) became widely discussed only after the first publicized U.S. sighting in 1947. Many thousands of such observations have since been reported worldwide.

    At least 90 percent of UFO sightings can be identified as conventional objects, although time-consuming investigations are often necessary for such identification. The objects most often mistaken for UFOs are bright planets and stars, aircraft, birds, balloons, kites, aerial flares, peculiar clouds, meteors, and satellites. The remaining sightings most likely can be attributed to other mistaken sightings or to inaccurate reporting, hoaxes, or delusions, although to disprove all claims made about UFOs is impossible.

    From 1947 to 1969 the U.S. Air Force investigated UFOs as a possible threat to national security. A total of 12618 reports were received, of which 701 reports, or 5.6 percent, were listed as unexplained. The air force concluded that "no UFO reported, investigated, and evaluated by the Air Force has ever given any indication of threat to our national security." Since 1969 no agency of the U.S. government has had any active program of UFO investigation.

    In 1997 the U.S. Central Intelligence Agency (CIA) admitted that the U.S. military had deceived the American public in an effort to hide information about high-altitude spy planes. These planes, the Lockheed U-2A and the Lockheed SR-71, accounted for over half of the UFO reports during the late 1950s and 1960s.

    Some persons nevertheless believe that UFOs are extraterrestrial(地球外的)spacecraft, even though no scientifically valid evidence supports that belief. The possibility of extraterrestrial civilization is not the stumbling block; most scientists grant that intelligent life may well exist elsewhere in the universe. A fully convincing UFO photograph of a craftlike object has yet to be taken, however, and the scientific method requires that highly speculative explanations should not be adopted unless all of the more ordinary explanations can be ruled out.

    UFO enthusiasts persist, however, and some persons even claim to have been abducted and taken aboard UFOs. A close encounter of the third kind is UFO terminology for an alleged encounter between humans and visitors from outer space. No one has produced scientifically acceptable proof of these claims.

(389 words)

    1. UFOs ______.( C )

(a) became widely known long before 1947

(b) are often mistaken for planets

(c) are for the most part nothing unusual

(d) cannot be identified

2. The cause of UFO seems to be related to _______.( A )

(a) illusions

(b) imaginations

(c) conventions

(d) false reports

3. According to the U.S. Air Force, ___________.( A )

(a) UFOs constitute no threat to the American national security

(b) 5.6% of the reported UFOs are dangerous to the American national security

(c) 10% of the UFO reports turned out to be nothing unusual

(d) the government should do more investigation of UFO

4. The U.S Central Intelligence Agency ________. ( B )

(a) confessed to having cheated the American public into believing the existence of UFO

(b) concealed facts about spy planes

(c) declared that spy planes take up over 50% of the total 12 618 reports

(d) revealed that they began launching spy planes in the late 1950s

5. The existence of extraterrestrial spacecraft ______. ( D )

(a) is held true by most people, including some scientists

(b) is firmly supported by a UFO photograph

(c) can be proved true by the existence of extraterrestrial culture.

(d) does not hold water scientifically   

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Passage Two

    On a cool September morning, two men began to climb a nearly vertical slope rising over 2200 feet from the floor of Yosemite National Park. Because of the slope's crumbly granite, fewer than 30 people have completed this particular route up Half Dome, Yosemite's well-known landmark. What made this particular climb very difficult and dangerous was that one of the men, Mark Wellman, is a paraplegic.

    Some years ago, on a different climb, Mark fell 50 feet into a crevice, hurt his back, and was paralyzed from the waist down. Mark now climbs with his friend Mike Corbett, who takes the lead and sets the supports. Because Mark's legs are paralyzed, he climbs by using the supports to pull himself up inch by inch.

    Mark figured that by doing the equivalent of 5 000 pull-ups, each of which would raise him about 6 inches, he could climb the 2 200 feet in seven days. By the end of day seven, however, Mark and Mike were only a little more than halfway up the slope and had to sleep by hanging in sleeping bags anchored to the sheer granite wall.

    By day ten, Mark was becoming exhausted as his arms strained to raise his body's weight up the vertical face. By day 12, the men were almost out of food and water. Finally, on day 13, six days later than planned, Mark pulled himself up the last 6 inches and over the top of Half Dome. When Mark was asked later why he still climbed and risked further injury, he said, "Everyone has their own goals. Never under-estimate a person with a disability."

(271 words)

    6. Fewer than 30 people have completed the climb because ______. ( C )

(a) the route is nearly vertical

(b) the top is 2 200 feet high

(c) the granite of the slope might break apart at any time

(d) the climbing might paralyze people

7. This climb is particularly difficult because ______. ( B )

(a) they decided to climb it on a cool September morning

(b) one of them is disabled in both legs

(c) only fewer than 30 people have ever completed the climb

(d) they have to do without food and water

8. While going up the slope, Mark ______. ( D )

(a) took the lead in the climb

(b) followed his teammates in the climb

(c) climbed the slope with the help of both his hands and legs

(d) raised his body with his hands

9. Mark managed to climb to the top of Half Dome ______. ( D )

(a) in six days

(b) as planned

(c) by almost 10 000 pull-ups

(d) six days more than expected

10. The word "paraplegic" means ______. ( C )

(a) severely disabled

(b) with the body paralyzed

(c) paralytic of the legs and lower part of the body

(d) seriously ill   

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Passage Three

    The Swedish Space Corporation and the European Space Agency (ESA) have signed a $32.9 million contract to develop the Small Advanced Research and Technology 1 (Smart 1) science and technology demonstration spacecraft. Smart 1 will be launched to the moon in about 2003.

    The Smart series of small European spacecraft will prepare ESA for future missions, demonstrating innovative and key technologies, using common spacecraft platforms and equipment for maximum efficiency and cost savings.

    Using the moon as its target, Smart 1 will demonstrate how ion propulsion could propel a future craft into orbit around the planet Mercury, the largely unexplored inner planet of the solar system. The Smart 1 solar electric propulsion demonstration will mean Europe will not be dependent on the USA for this major new technology. The craft will also demonstrate other new technologies, including an autonomous star tracker and a miniature imaging camera.

    Other instruments to observe the lunar surface include an infrared spectrometer for planetary geology, an imaging X-ray spectrometer for surface elemental composition, and space plasma (等离子体) instruments.

     Smart 1 will be placed into a geostationary transfer orbit and will fire the xenon ion（氙离子） propulsion system to gradually increase the orbit. After about 200 days in space, its flightpath will rendezvous（会合）with the moon and the craft will enter orbit around it naturally under the influence of lunar gravity.

(226 words)

11. Smart 1 will be developed _______________. ( C )

(a) by the ESA

(b) by the Swedish Space Corporation

(c) jointly by the ESA and the Swedish Space Corporation

(d) by another organization not mentioned

12. The Smart series will _______.                  ( D )

(a) be launched to Mercury in 2003

(b) use the latest technologies

(c) use special platforms and equipment

(d) achieve maximum efficiency with minimum cost

13. According to the passage, __________. ( B )

(a) the star tracker in Smart 1 is the first of its kind in the world

(b) Smart 1 will remain in the geostational transfer orbit for about 200 days

(c) Europe will be more advanced in technology than the US

(d) Smart 1 will go into orbit naturally

14. Instruments used to observe the lunar surface include all the following EXCEPT _____.( A )

(a) ion propulsion

(b) an autonomous star tracker

(c) an infrared spectrometer

(d) a miniature camera

15. The suitable title for the passage is : ______. ( B )

(a) New Instruments to Observe Moon

(b) Sweden Signs Contract to Develop Smart for ESA

(c) How Smart 1 Works

(d) The Swedish Space Corporation and Smart   

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