What relationship can be seen between the mass and the volume of an object?

Which of the following is a testable hypothesis? a. if i brush my teeth, i will get fewer cavities than if i don't brush my teeth. b. green toothpaste tastes better than blue toothpaste or red toothpaste. c. smart, careful, healthy people always brush their teeth. d. it's wrong to not brush your teeth before you have an important conversation with someone.

Embryos of different species look very similar, which shows that the organisms share a ancestor.

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion