The ancestral mollusk was a small creature with a tiny shell, How did the struggle for survival create so many different types of modern molluscs?

How many variables are altered in a good experiment? a.1 b.0 c.2 d.3

Compare and contrast region e in the illustration above with region d. describe the physical characteristics of each region.

Molecular models of two different substances are shown below. in the molecule on the left, the oxygen atom pulls on electrons more strongly than the hydrogen atoms. in the molecule on the right, the two oxygen atoms pull on the shared electrons with the same strength. water molecule, h, o oxygen molecule, oz when the two substances are put in the same container, they do not attract each other. why does this happen? a. they both contain oxygen. b. one is polar and one is nonpolar. c . they are both polar. d. they contain different elements.