There are four important warning signs that should prompt you to talk to a health care provider. 1  Pain. Pain from arthritis can be constant or it may come and go. 2  Swelling. Some types of arthritis cause the skin over the affected joint to become red and swollen, feeling warm to the touch. 3  Stiffness.
There's a whole lot of water on Earth! Something like 326,000,000,000,000,000,000 gallons (326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 liters) can be found on our planet. This water is in a constant cycle -- it evaporates from the ocean, travels through the air, rains down on the land and then flows back to the ocean.
The water in rivers is much less salty than that in the ocean. Typically, the salt content in rivers is about 100 parts per million and the ocean is approximately one thousand times as salty. However, when river water enters the ocean, the water evaporates and the salt is left behind. Over time, the total amount of water in the oceans reaches an equilibrium amount. In any given year, let us say that 60 inches of rain falls, on average, across the earth, but the same amount of water evaporates.