An Energy Booster
When you train, your body loses the essential vitamins and nutrients necessary to function properly. For many years, athletes have compensated for this loss by drinking beverages designed to restore and rehydrate what the body loses. One such substance (34) has been on the market as a nutritious substitute is the sports drink Gatorade. Gatorade got its start back in 1965, when (35) medical researchers at the University of Florida were asked by the football team to find a dietary (36) that would help keep the players energetic during the long, hot practices in the Florida heat. The doctors went about experimenting to create a new, healthy sports drink. (37) it took a lot of work, they eventually came up with a drink that helped improve athletes’ endurance. The team decided to call the drink ‘Gatorade’. Soon, the entire team started drinking Gatorade regularly, and to prove the (38) of the new tonic, the Gators went on to win the Orange Bowl in 1967.

Dogs originally came from wolves. Wolves look a lot like dogs, but they are bigger. They are also quite fierce. At some point, some wolves changed through evolution. Some of them were smaller and gentler. These nicer wolves were the first dogs. No one knows for sure when this happened or why. Some people say it happened naturally over 50,000 years ago. Others say people made it happen between 15,000 and 50,000 years ago.
However, they came to be, people quickly saw that dogs were useful. Scientists who study humans say the first tamed dogs appeared with humans about 13,000 years ago in the Middle East. Not long after there were dogs in Asia, Africa, Europe and eventually, North America. These dogs were probably used mostly for hunting and traveling. They were also good companions.
Dogs were an important part of life in ancient Egypt. Egyptian dogs were used not only for hunting but as guards and warriors as well. They believed the god that guarded hell was a dog. Ancient Egyptians also named their pet dogs. Some popular names meant Brave One, Reliable, North-wind, Blacky, and Useless. Dogs were also good ancient Roman warriors. The Roman army used dogs all over Europe. Sometimes the dogs were attack dogs, but other times the dogs were messengers.
There are many different kinds of dogs today. How could they all come from wolves? There are many different explanations. Some scientists believe that dogs mixed with other animals from the Canidae family. This includes coyotes, foxes and jackals. Most scientists also believe that evolution and breeding influenced the variation. Later, people found breeds of dogs they liked and combined them to make all new breeds. In this way, people are still helping new breeds to appear today!

In the United States, air-conditioning has influenced the movement of population from the cooler northern states to the southern ones. Since air-conditioning made life more pleasant in the summer months, states like Florida and Arizona began to draw people from the north. This population shift has affected regional economies between northern and southern states.
The effects of air-conditioning on society are hardly limited to the United States. Singapore's Senior Minister, Lee Kuan Yew, claims that air-conditioning is one reason for Singapore's rise as an Asian power. In his view, societies in the past progressed most rapidly in countries with cooler climates, but now that countries in tropical zones are using air-conditioning, they can also expand and grow. The use of air-conditioning is seen in some Asian countries as a way to show status. In Hong Kong, for example, office managers tend to keep temperatures extremely cold, sometimes at only 60°F (16°C), 10 to 14°F (6 to 7°C) below the recommended settings. The main reason is simply to show that the company can afford it.
Although air-conditioning has led to economic improvement and has increased daily comfort for people everywhere, its impact on the environment has not been so positive. First, air conditioning units release polluting chemicals into the air, which contribute to global warming. Furthermore, running air-conditioning on a large scale requires enormous amounts of energy. The burning of coal and oil to produce this energy also contributes to air pollution and thus, to global warming.
In some countries, governments and industry are beginning to search for ways to reduce the harm caused by air-conditioning. In Japan, summer temperatures have been raised in office buildings to conserve energy. In the United States, government, industry, and private groups are searching for ways to reduce the amount of dangerous chemicals released by air conditioners. Staying cool is important, and many cannot imagine life without air-conditioning. However, new technologies are to be found to make sure that air-conditioning does not create more problems than it solves.
(Adapted from Advanced Reading Power by B.S. Mikulecky and L. Jefferies)