Valves, they are like flaps of muscle that keeps the blood in its place util its ready to be pumped along.
Its 3 of the same molecule.
The oncogenesis process is caused by these mutations in the genetic material of normal cells, which alter the normal balance between proliferation and cell death. As a result there is an uncontrolled cell division and an evolutionary process of these cells through natural selection within the organism. Rapid and uncontrolled reproduction of cells can produce benign tumors and some types of these tumors can become malignant, which is what is known as cancer. Benign tumors do not spread to distant parts of the body or invade other tissues, and usually do not pose a threat to life unless they compress vital structures or have some physiological activity (for example, that they are capable of producing a hormone) . Malignant tumors are able to invade other organs, spread to distant places (a process known as metastasis) and become a threat to life.
<span>The event that a "the first male has had a kidney stone" and b "the second male has had a kidney stone" is true. Random selection is used by the medical researcher in selecting two males from the population. Since simple random sample is defined as a subset of a statistical population wherein each member has an equal probability of being chosen, even if the probability is only 8%, males a and b may really have had a kidney stone. </span>
Alternating current electricity. This allowed electricity to flow further than Edison's first DC approach.
Railroads - allowed for transportation of materials to growing small cities, and large cities to become larger.
Antibiotics and antiviral medicines. - stopping deadly diseases and bacteria from spreading. This helped with many problems that would normally terminate 33% of populated areas that are infected.