Calcium and magnesium dissolved in water are the two most common minerals that make water "hard." The degree of hardness becomes greater as the calcium and magnesium content increases and is related to the concentration of multivalent cations dissolved in the water.
A warm up consist of a period of non-strenuous activity that slowly prepares the body for more vigorous exercise.
Most warm up will gradually increase in intensity. The muscle which was used can be different for each activity. <span>Not only athlete, </span>singer can do warm up too.
Answer: Demi Lovato -bipolar disorder
Explanation: