Answer:
In the 1960s, scientists found evidence that new material is indeed erupting along mid-ocean ridges. The scientists dived to the ocean floor in Alvin, a small submarine built to withstand the crushing pressures four kilometers down in the ocean. In a ridge’s central valley, Alvin’s crew found strange rocks shaped like pillows or like toothpaste squeezed from a tube. Such rocks form only when molten material hardens quickly after erupting under water. These rocks showed that molten material has erupted again and again along the mid-ocean ridge.
When scientists studied patterns in the rocks of the ocean floor, they found more support for sea-floor spreading. You read earlier that Earth behaves like a giant magnet, with a north pole and a south pole. Surprisingly, Earth’s magnetic poles have reversed themselves many times during Earth’s history. The last reversal happened 780,000 years ago. If the magnetic poles suddenly reversed themselves today, you would find that your compass needle points south.
Explanation:
I found this somewhere.
Arthritis
Arthritis is a joint disorder in
which there is inflammation of one or more joints. Arthritis is frequently accompanied by joint
pain. There are many types of arthritis and over 100 have been identified. The causes
of arthritis include injury, metabolic abnormalities, hereditary factors,
effect of infections, and a misdirected immune system. Arthritis is mostly
common among women and occurs as people get older. Severe arthritis can result
in chronic pain, inability to do daily activities and can cause difficulty in walking.
Cardiac Muscle Tissue<span>. Cardiac </span>muscle tissue<span> is an extremely specialized form of </span>muscle tissue<span> that has evolved to pump blood throughout the body. In fact, cardiac </span>muscle<span> is only found in the</span>heart<span> and makes </span>up<span> the bulk of the </span>heart's<span> mass.</span>
