等边三角形有几条对称轴？请选择ABCD3B5S7{-F6n(k0@4|3p,]-K6K/a;t4Z-W1L1e(j9G8Q
A．1/a;t4Z-W1L1e(j9G8Q
B．2/a;t4Z-W1L1e(j9G8Q
C．3/a;t4Z-W1L1e(j9G8Q
D．无数/a;t4Z-W1L1e(j9G8Q