[填空题]
A 70-kg patient is to be given a medicalds+ 9d5 3d khwvaid,9g test involving the ingestion orv2z owb y.-j6 z53 ovfto2j-lf $_{43}^{99\text{m}}\text{Tc}$ (Section 31-7) which decays by emitting a 140-keV gamma. The half-life for this decay is 6 hours. Assuming that about half the gamma photons exit the body without interacting with anything, what must be the initial activity of the Tc sample if the whole-body dose cannot exceed 50 mrem? Make the rough approximation that biological elimination of Tc can be ignored. Activity $\simeq $ $\ \text{mCi}$
