普通混凝土常用的水泥有硅酸盐水泥、矿渣水泥、普通水泥等三大类水泥。( )
参考答案:错
This contract is made ______ Dalian International Economical Trade Co. and Kich boro International Limited.
A.among
B.between
C.with
D.by
能使α-葡萄糖苷键水解的酶是()
A.麦芽糖酶
B.苦杏仁苷酶
C.纤维素酶
D.均可以
E.均不是