采用火焰原子吸收光谱法测定食品中铅的国标法规定:在一定pH条件下,与什么形成络和物,然后萃取测定()
A. 二乙基二硫代氨基甲酸银
B. 二乙基二硫代氨基甲酸钠
C. 硝酸银
D. 硫脲
E. 碘化钾
驱动桥由主减速器、半轴、差速器和驱动桥壳组成,其功用是将万向传动机构传来的发动机转矩传给驱动车轮,实现降速、增大转矩。
A. 正确
B. 错误
The importance of the distinction between a charter by demise and a charter party proper()that under the former the master is the agent of the Charterer,not of the Shipowner.
A. has
B. have
C. is
D. are