[填空题]
At approximately what time had ydk9m r+wz)p45cu)a ta de7z7the uno0f2osj1rbjnh1(l m-y,1q n siverse cooled below the threshold temperature f oly2j0s1q nb1, s-f ohmjr1(nor producing
(a) kaons ($m c^2 \approx 493\ \text{MeV}$), $\sim 10^{a}\ \text{s}$ a =
(b) $\Xi$ baryons ($m c^2 \approx 1321\ \text{MeV}$), $\sim 10^{a}\ \text{s}$ a =
(c) muons ($m c^2 \approx 106\ \text{MeV}$)? $\sim 10^{a}\ \text{s}$ a =
