硬质玻璃贮样容器宜于贮存有机物水样、生物水样及六价铬、硫化物、()等项目的水样。
A、氨
B、钾
C、钠
D、钙
参考答案:A
_________ no doubt that a green campus plays an important role in the growth of students, both physically and mentally.
A.It is
B.There has
C.There is
D.It has
进出口货物收发货人在报关注册登记后取得报关权,可以接受他人委托代理其办理报关纳税手续。( )