The boy is ________ see the teacher because he ________ a mistake.
A：afraid of; has
B：afraid to; has made
C：afraid to; make
D：afraid of; made
某一行星有一质量为m的卫星，已知卫星的轨道半径为R，周期为T，万有引力常量为G．求：
小兵有32张动物邮票，每页放6张，可以放几页，还剩多少张？
用一个平面去截下列几何体：①正方体；②圆锥；③圆柱；④正三棱柱，得到的截面形状可能为三角形的有____（写出所有正确结果的序号）
