(2013·高考湖南卷)If nothing ，the oceans will turn into fish deserts.
A. does
B. had been done
C. will do
D. is done
网友回答
A. does
B. had been done
C. will do
(答案→)D. is done
解析：选D。题干的意思是：“如果什么措施都不采取的话，海洋将会变成鱼类的沙漠。”根据“主将从现”的原则，即主句为一般将来时，从句用一般现在时，再根据语境可知此处应用被动语态，故答案为D。