Why is the cell theory a theory and not a law?

the cell theory explains the natural world.
the cell theory describes the natural world.
the cell theory has not been tested enough by the scientific community.
the cell theory has not been accepted by the scientific community.

What mistake did john needham make that caused him to conclude that spontaneous generation for microorganisms occurred? a. he re-contaminated his boiled broth solutions. b. he destroyed the vital force in the solutions. c. he did not boil his broth solutions, only warmed them. d. he failed to seal his flasks of boiled broth. e. he allowed his assistant to conduct the experiment which he did not monitor closely.