[填空题]
What minimum kinetic energy must tw;3 krjoul r2rx h/39ixo neutrons each hav7x9aewq58vi:t3npj1qqv.o (b6e wpn e if they are traveling at the same speed toward each other, collip p9i. wvtb:( aq1j6vqxwe7e5o3q8nn de, and produce a $\pi^0$ pair in addition to themselves? (See Table 32-2.) MeV
