单项选择题
A.78eV ,49eVB.0.78eV ,4.9evC.7.8eV ,49eVD.0.78eV ,49eV
A.540.4kevB.54.04kevC.5404kevD.5.404kev
A.4.87MeV,4.78MeVB.48.7MeV,47.8MeVC.4.87MeV,47.8MeVD.48.7MeV,4.78MeV