In your own words, please explain why does the ocean crust sink?

(Note- The image below should be able to help you out a bit if you're having trouble)

oceanic crust sinks because it is denser and has higher specific gravity than the more silicon aluminum enriched continental crust.

Explanation:

the answers for the whole quick check is

1. b

2. b

3. a

4. c

5. b

6. a

7. d