問題詳情

19.One should read books on ecology ___ about the threats to his environment.___________
(A)to learn,
(B) for the sake of learning
(C) will learn
(D) so that he shall learn"

參考答案

答案：[無官方正解]
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)