問題詳情

19. If people take things from the earth just enough for their life, or never take more than they need, then the _______ of life will keep going forever.
(A) circle
(B) ring
(C) key
(D) wallet

參考答案

答案：A
難度：非常困難0.125
統計：A(1),B(1),C(1),D(3),E(0)