《捕蛇者说》一文最大的特点是运用____,将蒋氏的遭遇和乡邻们作____突出文章主旨。
(Ⅰ) 证明:CD⊥平面A1OC;
(Ⅱ) 若平面A1BE⊥平面BCDE,求平面A1BC与平面A1CD夹角(锐角)的余弦值.
下列能证明海陆变迁的自然现象是( )
Dear students, please read every sentence carefully. _______ you are, _______ mistakes you’ll make.