尼泊尔地震后，防疫人员将动物尸体集中焚烧或掩埋，这种做法属于传染病预防措施中的（ ）

① $\frac{5}{8}$ ②0.62③62.1%④ $\frac{2}{3}$ ．

（Ⅰ）试问在线段BE上是否存在点M，使得直线AF∥平面MNC？若存在，请证明AF∥平面MNC，并求出 $\frac{BM}{ME}$ 的值，若不存在，请说明理由；

（Ⅱ）求二面角N﹣CE﹣D的正弦值．

根据材料内容，选择正确答案。  

    There are 50 students in Class 8. Now they are doing a survey about how they spend their pocket money. Some spend it on books, and others spend it on visiting. What about you? Please read the form and answer the questions.