8加上x的5倍的和是(8+x)×5.
一 Could you tell me ? I must find him.
一Sorry, I'v no idea. But he was here just now.
(Ⅰ)求证:平面BCM⊥平面ACM.
(Ⅱ)若平面ABM⊥平面BCM,求三棱锥B﹣ACM外接球的直径.
下列过程放出热量的是( )
哪怕只是吃饭比别人快,起床比别人早,甚至是体操做得比别人好,都可以作为自信的源泉。这告诉我们 ( )