History & Culture. In April 1917, the United States entered World War I on the side of the Allies. Previously angered by the sinking of Lusitania, President Woodrow Wilson led the nation to war after learning of the Zimmermann Telegram and Germany's resumption of unrestricted submarine warfare.
WATER AND HUMANS. * The human body is more than 60 percent water. Blood is 92 percent water, the brain and muscles are 75 percent water, and bones are about 22 percent water. * A human can survive for a month or more without eating food, but only a week or so without drinking water.
The composition of the human body can be looked at from the point of view of either mass composition or atomic composition. To illustrate both views, the adult male human body is approximately 57% water, and water is 11% hydrogen by mass but 67% by count of atoms (i.e. 67 atomic percent). Thus, most of the mass of the human body is oxygen, but most of the atoms in the human body are hydrogen atoms.