[填空题]
(a) How much energy is released when an :lnj nw27snt+bg k0x- e2v4pwxm7i e;electron and a positron annihilapxr6m57ht ok; te each om6t5xpo h; r7kther? $E_{\text{total}}$= MeV
(b) How much energy is released when a proton and an antiproton annihilate each other? (All particles have $KE = 0$.) $E_{\text{total}}$ = MeV
