如图,AB是⊙O的直径,弦CD⊥AB,垂足为E,如果AB=20,CD=16,"那么线段OE的长为()
A:10
B:8
C:6
D:4
There are two birthdays in August. (改为一般疑问句)
____ two birthdays in August?
某生物兴趣小组观察了几种生物不同分裂时期的细胞,并根据观察结果绘制出如下图形.下列与图形有关的说法中正确的是( )