Question

【题目】If nothing ________, the oceans will turn into fish deserts.
A.does
B.had been done
C.will do
D.is done

Answer 1

【答案】D
【解析】句意：如果不采取措施，海洋将变成鱼的沙漠。If引导的条件状语从句中：nothing作主语，和谓语动词原型do构成逻辑上的被动关系，用被动语态。