Distingquish between codon and anit codon

Four types of motile cells in human body?

Which statement is true about the cell theory? a) it is well-supported by evidence. b) it is unchangeable and permanent.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere