問題詳情

21. We can never expect ________ bluer sky unlesswe create ________ less polluted world.
(A). a; a
(B). a; the
(C). the; a
(D). the; the

參考答案

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