= Solution
Use $w,x,y$ as the three select <bits> of the 8-to-1 <multiplexer>, so address $i=4w+2x+y$ selects data input $D_i$. Connect
$$
\boxed{(D_0,D_1,D_2,D_3,D_4,D_5,D_6,D_7)=(\bar z,1,z,\bar z,1,0,0,0).}
$$
A single <NOT gate> produces $\bar z$, shared by $D_0$ and $D_3$; the other connections are wires and constant logic levels. For each fixed select address the data input reproduces the corresponding two rows of the <truth table>, including zeros for all invalid codes.
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