Which tow items common in europe did the conquistadores introduce to the people of mesoamerica and south america

The correct answer here would be guns and horses.

Both the guns and horses made the conquistadors a force to be reckoned with and inspired both the fear and awe among the native populations. The peoples of Mesoamerica had never seen horses and they certainly have never seen guns before as their technology was not developed enough. They were still using weapons like bows.