A.10%~30% B.20%~40% C.30%~50% D.40%~60% E.50%~70%
A.Becquerel B.Cassen C.YaloW D.YaloW和Berson E.Berson
A.α衰變 B.β-衰變 C.γ衰變 D.β+衰變 E.電子俘獲