②以上底面A1B1C1D1的对角线交点为原点建立x′,y′,z′轴,如图b所示,在z′上取点V′,使得V′O′的长度为棱锥的高,连接V′A1,V′B1,V′C1,V′D1,得到
如图漫画给我们的启示是( )
“▲8848米”表述正确的是( )
— Why don't you ________ a hobby like painting or taking photos?