问题
选择题
Scientists should _____ new ways to solve the pollution problem.[ ]
A. catch up with
B. come up with
C. keep up with
D. make up with
答案
答案：B
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Scientists should _____ new ways to solve the pollution problem.[ ]
A. catch up with
B. come up with
C. keep up with
D. make up with
答案：B
