[填空题]
(a) AM radio signals zf pv5smd-y:s9ij dl rug14: 0g5(hhehave freq txjxix9 ie3.4uencies between 550 kHz and 1600 kHz (kilohertz) and trax9xii 3j.4et xvel with a speed of $ 3\times10^{8 }$ m/s What are the wavelengths of these signals? m to m(b) On FM, the frequencies range from 88.0 MHz to 108 MHz (megahertz) and travel at the same speed; what are their wavelengths? m to m