問題詳情
【題組】67. Currently fuel cells are powered by __________.
(A) advanced and expensive materials
(B) newly-found chemicals
(C) materials that are highly technological
(D) waste materials that would not be used
參考答案
答案：D
難度：適中0.5
統計：A(1),B(1),C(0),D(3),E(0)