[填空题]Until the very latest moment of his existence man has been
bound to the planet on which he originated and developed. Now he had 81 ______
the capability to leave that planet and move out into the universe to
those worlds which he has known previously only directly. Men have 82 ______
explored parts of the moon, put spaceships in orbit around another
planet and possibly within the decade will land into another planet 83 ______
and explore it. Can we be too bold as to suggest that we may be able 84 ______
to colonize other planet within 85 ______
the not-too-distant future Some have advocated such a precdure as a
solution to the population problem, ship the excess people off to the
moon. But we must keep in head the billions of dollars we might 86 ______
spend in carrying out the project. To maintain the earth’s population
at its present level. We would have to blast off into space