What is the diffence and the same of snake and worm

The difference is that the snake has scales and the worm has no scales, and how they are the same is that they both have no bones in their bodies

The independent variable is the type of music.the dependent variable is the pulse rate.the intervening variable is the age of the subject.if the mother does not like rock, her pulse is likely to not increase.the same might be true for the sister.the friend may like rap and gets excited.to establish cause/effect relationship, all of the subjects must be consistent.hope i .