圆柱体体积计算公式为（）。
A.πr^2
B.πΦ^2
C.πr^2·H
参考答案：C
No one can________how the election will turn out, as there are many unknown facts. [ ]
A. protect
B. prepare
C. prevent
D. predict
我们为什么要树立远大的人生理想？
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