問題詳情

17.The creation of helium within stars
(A)cannot be measured
(B)produces energy
(C)produces hydrogen as a by-product
(D)causes helium to be much more abundant In old stars than In young star:

參考答案

答案:B
難度:適中0.5
統計:A(0),B(3),C(1),D(2),E(0)

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