The "eight glasses a day" rule presumes 8-oz glasses:
8 x 8 = 64 oz = 2 quarts
1 quart = 946 ml x 2 = 1892 ml
So you should drink 3.784 of those 500ml bottles of water.
Looked at another way, each of those 8oz glasses of water holds 236.5 ml, so if you drink all four 500ml bottles of water, you're drinking a little more than 8 1/2 glasses of water.
Looked at a third way, if you measure an extra half-ounce of water into each of your eight glasses, you're up to four 500ml bottles.
Cooling down after your workout allows for a gradual recovery of preexercise heart rate and blood pressure.
This absolutely true.
The poor in America cannot afford nutritional food, healthcare and they live in dire situations. Crime and gangs are rampant amongst poorer neighborhoods which leads to homicide and drug taking, both of which impact on the life expectancy of people.