Ahypothesis is
a. much the same thing as a theory.
b. a question based on observations.
c. a series of connected observations.
d. a guess based on some knowledge.

What are some characteristics of a free enterprise economy?

Vaccines are weakened forms of disease causing microorganisms, which are given to patients to prevent disease. after the vaccine is administered, the immune system responds by creating a(n) to recognize the a.) antibody, antibiotic b.) antigen, antibody c.)antibiotic, antibody d.)antibody, antigen

Which describes the changes in the earths motion?