2. 外语
  3. A. attempt B. charged C. crucial D. delicate E. essentially F. eventually G. expended H. fraction I. individual J. maintain

A. attempt B. charged C. crucial D. delicate E. essentially F. eventually G. expended H. fraction I. individual J. maintain

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问题    A. attempt B. charged C. crucial D. delicate E. essentially
   F. eventually G. expended H. fraction I. individual J. maintain
   K. minority L. negligible M. scrapping N. slashing O. upsurging
   Space X launched a cheaper, partially-used rocket into orbit. That’s a stride toward 【C1】______the price tag of sending payload to space. Successfully flying reusable rockets is a 【C2】______step toward the dream of sending people to Mars. Until now, rockets have almost all been single-use. Once the fuel is【C3】______, a rocket stage plummets to Earth, resulting in the destruction of extremely expensive equipment that costs tens of millions of dollars to build.
   Its founder has likened that to 【C4】______a 747 jet after one flight, which would make air travel impossibly expensive. He has suggested that rocket launches could 【C5】______be much cheaper since the cost of the rocket propellants are less than 1 percent of the full-price ticket for a launch. So, if a rocket could be simply refueled like a jetliner for another flight, the cost of space travel could drop to a 【C6】______of what it is now. The stresses of spaceflight on reused boosters, however, are much greater than those on jetliners. The economics will depend on how many times a booster can be flown, and how much the 【C7】______expense will be to repair the booster each time.
   Reusable spaceships are not a new idea. NASA’s space shuttles were the first real 【C8】______at a reusable spaceship, but the shuttles proved more 【C9】______than hoped, requiring an army of technicians to 【C10】______them between flights. As a result, they ended up being more expensive than expendable rockets.
【C10】
选项
答案J
解析 分析句子成分可知，空格处为require sb．to do sth．结构，再结合空格后的宾语them可知，空格处应填入一个及物动词的原形。上一段提到，决定太空航行所需花费的关键性因素是每次维修所需要的花费，而下文提到，太空飞行比消耗性火箭昂贵得多，由此可以推断，太空飞行之所以昂贵是因为维修费用高，因此此处是说每次飞行后都需要大批技术人员进行整修，故J项maintain“维护；保养”为答案。
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