Which of the following is NOT a characteristic of amphoteric oxides?

Amphoteric oxides are unique compounds that exhibit both acidic and basic behavior. This characteristic allows them to react with both acids and bases. When considering the characteristics of amphoteric oxides, the correct understanding is that they can engage in reactions with acids and bases alike, demonstrating a dual reactivity.

The characteristic of only reacting with bases does not align with the definition of amphoteric oxides, as such behavior restricts their reactive potential and contradicts their amphoteric nature. By being able to react with acids, these oxides illustrate their capacity to participate in both acidic and basic reactions, thereby confirming that the statement about only reacting with bases does not apply to all amphoteric oxides and is therefore the correct choice for what is NOT a characteristic of them.