第二节语法填空 (共10小题；每小题1.5分，满分15分)
阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填人一个适当的词或使用括号中词语的正确形式填空，并将答案填写在答题卡标号为3l~40的相应位置上。
Scientists have found “significant” amounts of water in a crater (火山口) at the moon’s south pole, a major   31   (discover) that will dramatically revise the description of the moon   32  a dead world and likely make it a more attractive destination for future human space missions.
“The moon is alive,” declared Anthony Colaprete, the chief scientist for the Lunar Crater Observation and Sensing Satellite mission,   31   used a rocket on Oct. 9 to punch a hole about 100 feet across in the moon’s surface, and then measured about 25 gallons of water in the form of vapor and ice.   31  that’s not enough to swim in, it could indicate sufficient water in permanently shaded craters at the poles for future astronauts to live off the land.
NASA’s plans, currently under review by the Obama administration, call for   31   return to the moon at the end of the next decade, and   31  (construct) of a lunar base in which astronauts could live and work for months at a time.
The presence of large quantities of water would make that plan more   31   (practice), since water could be used for drinking, breathing and even making rocket fuel.   31 , a resource-rich moon could also serve as the perfect low-gravity launch-pad (发射台) for missions that would carry astronauts and   31   families elsewhere in the solar system,   31  (realize) the dreams of generations of science-fiction writers.