如果在滴定过程中发现滴定不到终点或指示剂加入后颜色呈灰紫色时，可能是Fe、Al、Cu或Mn等离子的干扰。（）
参考答案：对
公安执法监督的对象是( )。
A．公安机关及其人民警察
B．人民群众
C．危害社会治安的人
D．犯罪分子
What would most likely prevent a SART’s signal from being detected?（）
A.Signal absorption by the ionosphere
B.Heavy sea swells
C.The rescue personnel were monitoring the 10-cm radar
D.The rescue personnel were monitoring the 3-cm radar
