This has reduced the amount of wasted food at some schools38 percent.A. withB. toC. inD. b

问题补充：

This has reduced the amount of wasted food at some schools38 percent.

A. with

B. to

C. in

D. by

答案：

A. with

B. to

C. in

(答案→)D. by

解析：考查介词。reduce … to…减少到……；reduce … by …减少了……，根据句意选择D。