Answer:
2.5% of sea water is salt
What assignment do you need help with?
I don't know the context, but I believe the answer must be predicate adjective. If your sentence goes something like "This song is popular", popular is a predicate adjective because it goes together with a linking verb ("is"), and modifies the subject ("song"), telling us what the subject is, and not what it does.
How does Granholm end her speech "Remembering Rosa Parks"? ...
A speaker ENDS his or her speech with a call to action .
