All proteins are complex organic compounds that are composed of strands of 22 amino acids. Every living cell contains protein molecules. These are the most common substances in living things. Proteins can be identified by the many functions they perform. Enzymes, which are globular proteins, speed up a cell chemistry; transport proteins, such as hemoglobin, carry essential materials through the body; antibodies fight infection; and hormones control cell metabolism. Proteins are essential. Life as we know it would be impossible.

The predominant system of measurement in the United States is almost identical to that used in the United Kingdom. An American yard is the same length in inches as an English yard. A pound of meat in Chicago, Illinois, weighs a pound in Glasgow, Scotland. The American gallon is smaller than the British gallon. All other liquid measurements differ even though they may bear the same name. The capacity of an American quart bottle is less than that of its British cousin. Londoners fit more into their bushel than New Yorkers do. In the Los Angeles, California, a ton is 2,000 pounds. In Cardiff, Wales, it is 2,240 pounds. The British version is called the long ton, and the American is known as the short ton. When you fill up at a petrol station in Yorkshire, remember that each gallon might cost more than its Pennsylvanian counterpart, but it also contains about 20% percent more fuel.

Smallpox was once a highly contagious disease that killed millions. Epidemics wiped out hundreds of thousands of people in Europe and Asia. Indigenous populations in the Americas were decimated. The Aztec and the Inca suffered major smallpox epidemics upon contact with Spanish conquistadors. Smallpox contributed to the destruction of hundreds of thousands of indigenous peoples in the Americas during the sixteenth 16th century. The virialo virus causes smallpox. The disease had been called virialo. It was given its current name in the eighteenth 18th century to distinguish it from syphilis. Syphilis was known as the "great pox." Techniques to control the spread of smallpox had been known for a long time by the Chinese and the Turks, who ground smallpox scabs into powders, which were introduced into the bodies of healthy people so as to create an immunity. Until the very end of the eighteenth 18th century, Europeans had no way of fighting the disease. Epidemics abated only after the weakest and most susceptible of the diseased victims had died out. A vaccine was discovered by the British physician, Edward Jenner, in 1796. The disease continued to ravage peoples in poor countries. In 1966, The the World Health Organization launched a campaign to eradicate smallpox. The last reported case appeared in Somalia in 1977.