問題詳情

36. Farming becomes more expensive when farmers are forced to apply more costly fertilizers _______ yields.
(A) to sustain
(B)to be sustained
(C) which are sustained
(D)sustaining

參考答案

答案：A
難度：適中0.54023
統計：A(47),B(17),C(11),D(12),E(0)