（Ⅰ）求证：BM∥平面ADEF；

（Ⅱ）求三棱锥M﹣BDE的体积．

近年来我国地震不断，造成了重大人员伤亡和财产损失，当地震发生时，教室里学生采取的措施最合理的是（　　）

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                                                                                                                             己亥杂诗  龚自珍
                                                                                                                             浩荡离愁白日斜，

                                                                                                                             吟鞭东指即天涯。

                                                                                                                             落红不是无情物，

                                                                                                                             化作春泥更护花。