平台活动包括以下哪几种？（）
A.super deals
B.平台大促
C.行业主题活动
D.Hot&New各行业活动
参考答案：A, B, C, D
试述通货膨胀的社会经济影响。
The inside dimensions of a rectangular wooden box are 6 inches by 8 inches by 10 inches. A cylindrical cannister is to be placed inside the box so that it stands upright when the closed box rests on one of its six faces. Of all such cannisters that could be used, what is the radius, in inches, of the one that has maximum volume ？（）
A．3
B．4
C．5
D．6
E．8
