[填空题]
If the potassium iso r wsk5k2(xb0d7qp 60e4* dddlxir,h f*a ne*de3 gcg*k wa2e2.y 6-mbz-oomytope $_{19}^{40}\text{K}$ gives $60\ \text{decays/s}$ in a liter of milk, estimate how much $_{19}^{40}\text{K}$ and regular $_{19}^{39}\text{K}$ are in a liter of milk. Use Appendix B.
$m_{40}$ = $mg$
$m_{39}$ = $mg$
