The Earth's past climate, including temperature and elements in the atmosphere, has recently been studied by analyzing ice samples from Greenland and Antarctica. The air bubbles in the ice have shown that, over the past 160,000 years, there has been a close correlation between temperature changes and the level of natural greenhouse gases carbon dioxide and methane. One recent analysis from Greenland showed that at the end of the last glacial period (when the great ice sheets began to retreat to their present position), temperatures in southern Greenland rose from 5 to 7 degrees in about 100 years. Air bubbles are not the only method of determining characteristics of the Earth's ancient climate history. Analysis of dust layers from ancient volcanic activity is another such method; as is the study of ice cores, which interpret past solar activity that may have affected our climate. This passage states that:

French physicist Charles Fabry found ozone gas in the atmosphere in 1913. At room temperature, ozone is a colorless gas; it condenses to a dark blue liquid at -170 F. At temperatures above the boiling point of water, 212 F, it decomposes. Ozone is all around us. After a thunderstorm, or around electrical equipment, ozone is often detected as a sharp odor. Ozone is used as a strong oxidizing agent, a bleaching agent, and to sterilize drinking water. This gas is also highly reactive. For example, rubber insulation around a car's spark plug wires will need to be replaced eventually, due to the small amounts of ozone produced when electricity flows from the engine to the plug. The passage implies that:

Many people who have come close to death from drowning, cardiac arrest, or other causes have described near-death experiences--profound, subjective events that sometimes result in dramatic changes in values, beliefs, behavior, and attitudes toward life and death. These experiences often include a new clarity of thinking, a feeling of well-being, a sense of being out of the body, and visions of bright light or mystical encounters. Such experiences have been reported by an estimated 30 to 40 percent of hospital patients who were revived after coming close to death and about 5 percent of adult Americans in a nationwide poll. Near-death experiences have been explained as a response to a perceived threat of death (a psychological theory); as a result of biological states that accompany the process of dying (a physiological theory); and as a foretaste of an actual state of bliss after death (a transcendental theory). The primary purpose of this passage is to:

In most cases, little birds lay little eggs. The kiwi is an astonishing exception to this rule--it is a smallish bird that lays a big egg. The kiwi, a flightless bird found in New Zealand, weighs about four pounds, and its egg weighs, believe it or not, about one pound. That is one-fourth of the bird's body weight! If an ostrich laid an egg that was in the same proportion to the ostrich as the kiwi egg is to the kiwi, an ostrich egg would weigh a whopping seventy-five pounds instead of * the usual three pounds. Which statement below best describes the organizational method used in this passage?