The Galapagos Islands are in the Pacific Ocean, off the western coast of South America. They are a rocky, lonely spot, but they are also one of the most unusual places in the world. One reason is that they are the home of some of the last giant tortoises left on earth. Weighing hundreds of pounds, these tortoises, or land turtles, wander slowly around the rocks and sand of the islands. Strangely, each of these islands has its own particular kinds of tortoises. There are seven different kinds of tortoises on the eight islands, each kind being slightly different from the other. Hundreds of years ago, thousands of tortoises wandered around these islands. However, all that changed when people started landing there. When people first arrived in 1535, their ships had no refrigerators. This meant that fresh food was always a problem for the sailors on board. The giant tortoises provided a solution to this problem. Ships would anchor off the islands, and crews would row ashore and seize as many tortoises as they could. Once the animals were aboard the ship, the sailors would roll the tortoises onto their backs. The tortoises were completely helpless once on their backs, so they could only lie there until used for soups and stews. Almost 100,000 tortoises were carried off in this way. The tortoises faced other problems, too. Soon after the first ships, settlers arrived bringing pigs, goats, donkeys, dogs and cats. All of these animals ruined life for the tortoises. Donkey and goats ate all the plants that the tortoises usually fed on, while the pigs. Dogs and cats consumed thousands of baby tortoises each year. Within a few years, it was hard to find any tortoise eggs-or even any baby tortoises. By the early 1900s, people began to worry that the last of the tortoises would soon die out. No one, however, seemed to care enough to do anything about the problem. More and more tortoises disappeared, even though sailors no longer needed them for food. For another fifty years, this situation continued. Finally, in the 1950s, scientist decided that something must be done. The first part of their plan was to get rid of as many cats, dogs and other animals as they could. Next, they tried to make sure that more baby tortoises would be born. To do this, they started looking for wild tortoise eggs. They gathered the eggs and put them in safe containers. When the eggs hatched, the scientists raised the tortoises in special pens. Both the eggs and tortoises were numbered so that the scientists knew exactly which kinds of tortoises they had-and which island they came from. Once the tortoises were old enough and big enough to take care of themselves, the scientists took them back to their islands and set them loose. This slow, hard work continues today, and, thanks to it, the number of tortoises is now increasing every year. When did people start to do something to save the tortoises?
The amount of bone in the elderly ske|eton—a key determinant in its susceptibility to fractures-is believed to be a function of two major factors. The first is the peak amount of bone mass attained, determined to a large extent by genetic inheritance. The marked effect of gender is obvious: Elderly men experience only one-half as many hip fractures per capita as elderly women. But also, African- American women have a lower incidence of osteoporotic fractures than Caucasian women. Other important variables include diet, exposure to sunlight, and physical actMty. The second major factor is the rate of bone loss after peak bone mass has been attained. While many of the variables that affect peak bone mass also affect rates of bone loss, additional factors influencing bone loss include physiological stresses such as pregnancy and lactation. It is hormonal status, however, refilected primarily by estrogen and progesterone levels, that may exert the greatest effect on rates of decline in skeletal mass. It can be inferred from the passage that the peak amount of bone mass in women
SaIinger’s Catcher in the Rye, having become a manifesto for psychopaths and potential miscreants, is viewed by many high-school administrators as too to be suitable for teenage students.