Official 36 Lec 1
Question 5 of 6
Why does the professor mention digging a crater to find gold?

A.

To explain why many scientists are interested in new missions to the Moon

B.

To explain why helium-4 is more common on Earth than helium-3

C.

To explain why extracting helium-3 from lunar soil may not be practical

D.

To explain why scientists have looked for helium-3 in unusual places

正确答案:C

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