4. Why do some marine scientists specialize in single-celled organisms? (1 poi A. There are very few species to choose from
B. Single-celled organisms are the least understood in the ocean.
c. Many of them are poisonous, so they endanger other creatures.
d. Single-celled organisms form the foundation of life in the ocean.
5. Chemical oceanographers often study pollution because (1 point)
A. most pollution occurs in the ocean.
B. pollution creates chemical changes.
C. no other field examines the implications of pollution
D. only chemical oceanography uses the scientific method.