The new technology，if to farming，will help increase the grain output.
A. applying
B. to apply
C. applied
D. having applied
网友回答
A. applying
B. to apply
(答案→)C. applied
D. having applied
解析：
考查省略。if引导的条件状语从句中省略了与主句相同的主语及系动词，补全后为：if the new technology is applied to farming，因此选C。