镉试剂2B分光光度法测定水中银的检测上限为()mg/L.
A.0.8
B.1.0
C.1.2
D.2.0
参考答案:A
相差显微镜主要用于检查()
A.细菌运动方式
B.细菌鞭毛
C.细菌芽胞
D.细菌荚膜
E.细菌的形态及某些内部结构
Our school has a sports meeting ______ October 15th.
A. at
B. on
C. in
D. of