混凝土耐久性能检验取样数量应至少为计算试验用量的（）倍。
A.2.5
B.2.0
C.1.5
D.1.0
参考答案：C
This machine metal. [ ]
A. is made in
B. is made of
C. is made from
D. is made
最常引起无尿的是（）
A.肾前性肾衰
B.肾后性肾衰
C.急性肾性肾衰
D.前列腺增生症
E.膀胱肿瘤
