Scientists will have to come new methods of increasing the world’s food supply.A. up forB.

问题补充：

Scientists will have to come new methods of increasing the world’s food supply.

A. up for

B. up with

C. out

D. on

答案：

A. up for

(答案→)B. up with

C. out

D. on

解析：come up with表示想出的意思，与本题的题意相符，故本题选B。