¿Qué hay en el interior de las sustancias?

Forgot the question hahaha

Oh nskskakaaka

Well to my expert knowledge and my exquisite calculations i think the the negative ion # 412 is the key to sucess

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 .