球内接正方体的表面积与球的表面积的比为（ ）
A．6：π
B．4：π
C．3：π
D．2：π
设：正方体边长设为：a
则：球的半径为
，
a3 2
以球的表面积S1=4•π•R2=4π•
a2=3πa2，3 4
而正方体表面积为：S2=6a2，
所以球内接正方体的表面积与球的表面积的比为
=S2 S1
=6a2 3πa2
．2 π
故选D．
| 从方框中选出恰当的句子补全对话，有两项为多余项。 | |
B: You mean (指的是) the running star? A: Yes, the running star Sandra. B: Yes, I know a lot about her. 2 A: Oh? What does she have for breakfast? B: She likes eggs, bananas and apples. A: 3 B: She likes hamburgers, salad and oranges for lunch. A: And dinner? B: 4 A: 5 B: Yes, she likes ice cream for that. 1._____ 2._____ 3._____ 4._____ 5._____ |