单项选择题
A.光的反射现象B.光的全反射现象C.光的折射现象D.光的干涉现象
A.7.5×10-7m,3×108m/sB.5×10-7m,3×108m/sC.7.5×10-7m,2×108m/sD.5×10-7m,2×108m/s
A.AB.BC.CD.D