The world`s population is getting larger and larger,so scientists are trying to ______new ways to solve the food problem .A catch up with B keeo up withC come up withD make up with
问题描述：
The world`s population is getting larger and larger,so scientists are trying to ______new ways to solve the food problem .
A catch up with
B keeo up with
C come up with
D make up with
答