A rectangular freshwater fish tank is 60.00 cm long, 200.00 mm wide, and 200.00 m deep. What is the mass of the water it can hold?

Answer is to avoid experimental error

The mass has escaped into a gas which you can not see so the law stays true.

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 .