具有金属螯合作用的物质有（）
A.莱菔硫烷
B.植物雌激素
C.植酸
D.褪黑素
E.硫辛酸
参考答案：C, E
一 I'm sorry. That wasn't of much help.
一 Oh, _____. As a matter of fact, it was most helpful. [ ]
A. sure it was
B. it doesn't matter
C. of course not
D. thanks anyway
一旦发现有人触电后，周围人员首先应迅速采取拉闸断电等有效措施，尽快使触电者脱离电源。第四章P67
