干藏食品库的相对湿度，应控制在（）。A.85%-95% B.75%-85% C.50_爱下问搜题

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问题单项选择题

干藏食品库的相对湿度，应控制在（）。

A.85%-95%

B.75%-85%

C.50%-60%

D.50%-40%

答案

参考答案：C

选择题

So far nothing _____ Tom. I want to know the reason _______ he hasn’t written to me.

A．heard from; why 　

B．has been heard from; why

C．was heard from; that

D．has heard from; that

判断题

堆叠山石要使其平稳，只需用水泥砂浆塞入即可。