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　　A. will contribute more (1)_____ the solution of these grave problems

　　B. at a time when many children (2)______ this Earth are starving to death

　　C. I did not know that there are children (3)______ from hunger

　　You asked in your letter how I could suggest the expenditures of billions of dollars for a voyage to Mars, (4)_____. I know that you do not expect an answer such as "Oh, (5)_____, but from now on I will desist from any kind of space research until mankind has solved that problem!" In fact, I have known of famined children long before I knew that a voyage to the planet Mars is technically feasible. However, I believe, like many of my friends, that travelling to the Moon and eventually to Mars and to other planets is a venture which we should undertake now, and I even believe that this project, in the long run, (6)______ we are facing here on Earth than many other potential projects of help which are debated and discussed year after year, and which are so extremely slow in yielding tangible results.