問題詳情

15.Why does the author mention "cosmic rays't' in line 7?
(A)As part of a list of things containing helium
(B)As an example of an unsolved astronomical puzzle
(C)To explain how the universe began
(D)To explain the abundance of hydrogen in the universe

參考答案

答案:A
難度:非常困難0.166667
統計:A(1),B(0),C(0),D(5),E(0)

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