D.Gunman Kills 20 School Children 免费查看参考答案及解析 题目: 如图1,在Rt△ABC中,∠C=90o,BC=3,AC=6,D,E分别是Ac,AB上的点, 且DE//BC,DE=2,将△ADE沿DE折起到A1DE的位置,使A1C⊥CD,如图2。 (1)求证:A1C⊥平面BCDE; (2)求棱锥A1-CBED的体积。 免费查看参考答案及解析 题目: 一直角...
NEW -@WSJconfirms the@CIA&@DeptofDefensehave a new "secret" missile - the R9X, or "flying Ginsu" - which kills a selected target with 6 blades, but no explosive payload.-- "To the targeted person, it's as if a speeding anvil fell from the sky."https://t.co/DIQfnfJYDqpic.twitt...
Russian attack kills at least 3 in Kyiv as Ukrainian drone strikes set Russian fuel stores alight Gunman shoots dead 2 judges in Iran’s capital tied to 1988 mass executions Ski lift accident leaves 30 injured at Spanish resort in the Pyrenees The Latest Fran...
Russian attack kills at least 3 in Kyiv as Ukrainian drone strikes set Russian fuel stores alight Gunman shoots dead 2 judges in Iran’s capital tied to 1988 mass executions Ski lift accident leaves 30 injured at Spanish resort in the Pyrenees The Latest France’s Macron leads tributes ...