Question

ocean water and the air constantly exchange gases. co₂ can enter ocean water directly from the atmosphere. after dissolving in water, co₂ may either be absorbed by organisms or sink deeper into the ocean. carbon in the deep ocean may be stored as sediments on the seafloor. over time, carbon in the deep ocean is cycled back to the surface as the water circulates. co₂ at the oceans surface can move back into the air. but taken altogether, ocean activities are a net carbon sink. complete the sentences. carbon in the ocean may be stored on the __. over time, carbon cycles back to the and is released into the air. overall, the ocean more co₂ than it __.

Explanation:

1. From the text: "Carbon in the deep ocean may be stored as sediments on the seafloor." So the first blank is "seafloor".
2. From "Over time, carbon in the deep ocean is cycled back to the surface as the water circulates." So the second blank is "surface".
3. From "ocean activities are a net carbon sink" (a sink absorbs more than it releases), so the third blank is "absorbs" and the fourth is "releases".

Answer:

Carbon in the ocean may be stored on the \boxed{seafloor}. Over time, carbon cycles back to the \boxed{surface} and is released into the air. Overall, the ocean \boxed{absorbs} more CO₂ than it \boxed{releases}.