The standard reduction half-cell reactions are:
\[ \text{AgCl(s) + e}^- \rightarrow \text{Ag(s) + Cl}^-(\text{aq}); \quad E^\Theta = 0.22 \text{ V at 298 K} \] \[ \text{Ag}^+(\text{aq}) + e^- \rightarrow \text{Ag(s)}; \quad E^\Theta = 0.80 \text{ V at 298 K} \]Rearrange the following parts to form a meaningful and grammatically correct sentence:
P. a healthy diet and regular exercise
Q. are important habits
R. that help maintain good physical and mental health
S. especially in today's busy world