Dr Yuan makes possible one-third more of the crop in the same fields.
A. it; produce
B. it; producing
C. it; to produce
D. it; produced
网友回答
A. it; produce
B. it; producing
(答案→)C. it; to produce
D. it; produced
解析：本题考查make it possible to do的用法，其他不符合语法结构。make it possible to do 使做某事成为可能。 此处it是形式宾语，真正的宾语是to produce one-third more of the crop in the same fields。