第5部分:补全短文(第46~50题,每题2分,共10分)
阅读下面的短文,文章中有5处空白,文章后面有6组文字,请根据文章的内容选择5组文字,将其分别放回文章原有位置,以恢复文章原貌。请将答案涂在答题卡相应的位置上。
Should the U.S. halt human apace flight?
The Columbia accident has revived the debate on whether the rewards of human space exploration are worth the risks No. I was a teacher when men first landed on the moon in 1969, and I remember how it moved my students and this country. _____(46) And we haven't ventured outward since then. That's 30 years too long! America's human space-flight program is adrift, with no clear vision or goals beyond the completion of the International Space Station.
I want NASA to establish a phased series of goals over the next 20 years, including human visits to asteroids that cross the Earth's orbit, establishing a research and living facility for humans on the moon, and human expeditions to the surface of Mars and its moons. _____(47)
An astronaut is today's Christopher Columbus, who sailed into the unknown and discovered the Americas. The knowledge we gain from having actual people exploring can never be replaced by robots. _____(48) Robots are useful, but humans can do things that robots can't.
The real obstacle we face in overcoming the drift in the nation's human space-flight program is not technological and it's not financial. _____(49)
The lesson from the Columbia accident is not that humans don't belong in space. _____(50)