I believe that in the blank should go "sabemos"
I hope I'm correct.
Answer:
Fuentes thinks that Spain would have not been wealthy without their easy victory over the Aztecs.
Explanation:
when it said " Para no hablar de las fabulosas riquezas que aquí hallamos y que, enviadas de Cádiz y Sevilla, hicieron la fortuna no solo de las Españas, sino en la Europa entera" meaning that the resources not only helped Spain become Wealthy but it helped all Europe
