老鹰铁与炉排间隙应为（）mm。
A.10
B.20
C.5
D.15
参考答案：B
She pretended me when I passed. [ ]
A. not to see
B. not seeing
C. to not see
D. having not seen
设f(x)在[a，b]上连续，a＞0，在(a，b)可微．证明在(a，b)内存在ξ使
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