如图,菱形ABCD由6个腰长为2,且全等的等腰梯形镶嵌而成,则线段AC的长为( )
A:3
B:6
C:33
D:63
如图,均匀带正电的绝缘圆环a与金属圆环b同心共面放置,将a绕O点在其所在平面内旋转时,b中产生顺时针方向的感应电流,且具有收缩的趋势,由此可知,圆环a( )
I'm____. I have a small nose and a small mouth. I have small eyes too.