問題詳情
22. Carbon dioxide, which makes a ______ between us and the sun, prevents heat from getting out of the atmosphere easily, so the earth is becoming warmer.
(A). difference
(B). comparison
(C). connection
(D). barrier
參考答案
答案：D
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)