第6部分：完形填空（第51～65题，每题1分，共15分）
　　下面的短文有15处空白，请根据短文内容为每处空白确定1个最佳选项。
                             Solar Storm
　
　　At the end of October 2003, a sudden solar storm hit the earth. A solar storm refers to the large amounts of charged particles released into space_______（51） the solar energy increases. The release of the energy_______（52） place along with the activity of the sunspots with a cycle of: 11 years. This time, the _______（53） of the storm exceeded expectations.
　
　　This_______（54） of intense solar storm was caused by the eruption of a solar flare （闪光） and the ejection （喷发） of the solar corona （日冠） on October 28, 2003. Large amounts of charged particles moved 150,000,000 kilometers through space toward the_______（55） in 19 hours. They could affect aircraft roaming （漫游） in space.
　
　　The high-energy particles will_______（56） some of the parts of an aircraft. They may also cause it to fail. High-energy particles can threaten the safety of an aircraft at a high orbit. If an aircraft orbits at a lower orbit, it is_______（57） because it is under the protection of the earth's magnetic field.
　
　　A solar storm not only affects aircraft but also is a _______（58） to the environment and humans. The aerosphere and magnetic field of the earth can_______（59） humans from ultraviolet radiation and X-rays. While most of the X-rays are absorbed after they enter the aerosphere （大气层）, still a few can_______（60） the ground.
　
　　The geomagnetic storm caused by this round of solar storm reaches its highest level on the two_______（61） of the earth, which affects electricity supply of North America. Overexposure to_______（62） threatens the health of passengers on planes flying over the Polar Regions. If we fly in the sky during such a solar storm, it_______（63） we receive ten times the X-ray radiation. It's really damaging.
　
　　Scientists say a solar eruption is like the sun sneezing, which will make the earth_______（64） a cold. Though this natural force is irresistible, scientists can still_______（65） its movement accurately by monitoring. Facing successive solar storms, humans can't drop their guard.
　
　　51 A since         B when         C until              D though
　　52 A finds         B adjusts        C holds             D takes
　　53 A intensity    B height         C width            D density
　　54 A piece        B part             C round           D set
　　55 A star           B earth          C moon            D sun
　　56 A dominate    B develop      C damage         D descend
　　57 A safe           B dangerous   C comfortable   D manageable
　　58 A limit            B cause         C force            D threat
　　59 A separate     B benefit        C distinguish     D protect
　　60 A lose           B reach           C break           D prepare
　　61 A poles         B mountains     C rivers           D lakes
　　62 A light           B storm          C radiation       D pressure
　　63 A recommends   B means      C proposes      D advises
　　64 A turn            B stop           C become        D catch
　　65 A detect        B start           C experience    D change

答案:
　　51 B　52 D　53 A　54 C　55 B

　　56 C　57 A　58 D　59 D　60 B

　　61 A　62 C　63 B　64 D　65 A