Answer:
Some tumors are benign, which means they form in only one spot without spreading to surrounding tissue. Malignant tumors are cancerous and can spread to nearby tissue. As cancerous tumors grow, cancer cells can break off and travel throughout the body, forming new tumors.
Explanation:
Surface water is warmer than deep-ocean water. The deeper you go into the ocean the colder it is. This is because the warmth from the sun cannot reach the water near the bottom of the ocean.
Answer:
They can occur anywhere from thousands to billions of years.