Reseña de ciencia y tecnología

coral.

explanation:

coral. many marine organisms that produce calcium carbonate shells or skeletons are negatively impacted by increasing co2 levels and decreasing ph in seawater.

organisms are more likely to be more preserved in mud than sand because mud is moist and wet, while sand is very dry.

oxygen, selenium, tellurium, and polonium.

they're all from the same group as sulfur (group 16).