题目

A warm drink of milk before bed has long been the best choice for those wanting a good night’s sleep. But now a study has found it really does help people nod off—if it is milked from a cow at night.     Researchers have discovered that “night milk” contains more melatonin (褪黑激素), which has been proven to help people feel sleepy and reduce anxiety.     The study, by researchers from Seoul, South Korea, involved mice being fed with dried milk powder made from cows milked both during the day and at night.     Those given night milk, which contained 10 times the化学在生产和日常生活中有着重要的应用。下列说法不正确的是  A．明矾水解形成的Al(OH)3胶体能吸附水中悬浮物，可用于水的净化B．在海轮外壳上镶入锌块，可减缓船体的腐蚀速率C．MgO的熔点很高，可用于制作耐高温材料D．电解MgCl2饱和溶液，可制得金属镁