- En la librería se puede comprar leche.
However, this pairing may not logically fit, as a librería typically sells books, while leche (milk) is not commonly associated with it. Therefore, if you meant to suggest the appropriate context, a more fitting option might be:
- En la zapatería se puede comprar botas.
So the best complete sentence would be: "8. En la zapatería se puede comprar botas."