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%
参考答案:C
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
堆叠山石要使其平稳,只需用水泥砂浆塞入即可。