28 Which of the following are true statements?
(A)Electrons are a kind of electromagnetic wave.
(B)In vacuum higher frequency electromagnetic waves travel with higher speeds.
(C)Some electromagnetic waves have electric charge.
(D)Light speeds up when it moves from water into air.
(E)All electromagnetic waves travel at the same speed in vacuum.
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統計: 尚無統計資料
統計: 尚無統計資料