一个圆锥的母线长为4,中截面面积为π,则圆锥的全面积为____________.
题目分析:因为中截面面积为π,所以底面半径为2,圆锥的全面积=侧面积+底面积,即.
—Did you see Tom at the party?
—No, he_________by the time I got there.[ ]
A. left
B. was leaving
C. had left
D. has left
支撑掩护式液压支架适用于中等稳定和坚硬顶板。()