考博易错题（2019/10/8）_网考网(Netkao.com)

考博易错题（2019/10/8）

第1题：Did you ever see colored lights in the sky far (1) the earth Perhaps you saw these beautiful green, yellow, or red streaks (2) in the northern skies at night. Or (3) you have seen sheets or curtains of colored light. Sometimes the lights seem to wave in the winD、It is a truly amazing (4) . You may have seen the aurora borealis.
Some ancient people thought the lights (5) from goddesses riding through the sky with shining shields, but astronomers today know (6) . These scientists know that explosions on the sun cause the aurora borealis. From the explosions come (7) pieces of matter which spin around the earth. The small pieces cool and enter the earth’s air space and are drawn (8) the North and South Poles.
Once inside the earth’s air space, these small bits of matter (9) power in the form of light. Though you can see the aurora borealis only (10) , this amazing (11) of color continues during the day as well. Often you can even (12) it. Sometimes it causes strange noises on radio and television sets.
The auroras, or bright displays of light, take place near the poles of the (13) . This happens because the poles are like giant (14) . Those tiny bits of matter from the sun are drawn toward (15) . Scientists call auroras near the North Pole aurora borealis. The same kind of light (16) the South Pole is called aurora australis.
People living in (17) ofCanada,Alaska, and Greenland can see the aurora borealis almost every night.A、display of lights may (18) from just a few hours to several nights. Once, in 1958, a giant aurora was (19) from theArctic down toCubA、From east to west it stretched 250 miles.And in the other direction, from north to south, it (20) six thousand miles. This huge display was truly beautiful!
A、onB、in
C、at D、near

【单选题】： A B C D

This week marks the 10th anniversary of theAlar apple scare, in which manyAmerican consumers were driven into a panic following the release of a report by an environmental organization claiming that apples containing the chemicalAlar posed a serious health threat to preschoolers. The report was disseminated through a PR (Problem Report) campaign and bypassed any legitimate form of scientific peer review. Introduced to theAmerican public byCBS’ "60 Minutes," the unsubstantiated claims in the report led some school districts to remove apples from their school lunch programs and unduly frightened conscientious parents trying to develop good eating habits for their children.
Last month,Consumers Union released a report warning consumers of the perils of consuming many fruits and vegetables that frequently contained "unsafe" levels of pesticide residues. This was especially true for children, they claimeD、Like its predecessor 10 years earlier, theConsumers Union report received no legitimate scientific peer review and the public’s first exposure to it was through news coverage.
Not only does such reporting potentially drive children from consuming healthful fruits and vegetables, the conclusions were based on a misleading interpretation of what constitutes a "safe" level of exposure.Briefly, the authors used values known as the "chronic reference doses," set by the U. S.Environmental ProtectionAgency, as their barometers of safety. Used appropriately, these levels represent the maximum amount of pesticide that could be consumed daily for life without concern. For a 70-year lifetime, for example, consumers would have to ingest this average amount of pesticide every day for more than 25, 000 days. It is clear, as the report points out, that there are days on which kids may be exposed to more; it is also clear that there are many more days when exposure is zero. Had the authors more appropriately calculated the cumulative exposures for which the safety standards are meant to apply, there would have been no risks and no warnings.
Parents should feel proud, rather than guilty, of providing fruits and vegetables for their children. It is well established that a diet rich in such foods decreases the risk of heart disease and cancer. Such benefits dramatically overwhelm the theoretical risks of tiny amounts of pesticides in fooD、So keep serving up the peaches, apples, spinach, squashes, grapes and pears.

第2题：{{B}}Passage Three{{/B}}

考博习题练习

您正在结束答题