TOEFL listening test 304

18: What did the professor discuss about hard coral? a)It does not build reefs b)Finger Coral is an example c)It build reefs d)It is found in deep water 19: What does the professor say is damaging reefs? a)Pollution b)High sea temperatures c)Man d)All of the above 20: How does the professor describe the word polyp? a)A tiny animal that forms coal reefs b)It is part of the Marine ecosystem c)It does ot have the ability to