Most forest fires are caused by human carelessness or ignorance. Forest fire prevention, therefore, is mainly a problem of creating better understanding of the importance of forests, an awareness of the danger of fire in the woods, and a sense of personal responsibility to safeguard the forests from danger. This is not an easy job.
Careless smokers are responsible for thousands of forest fires each year. Many of these are started when cigarette butts(烟蒂) and matches are thrown from automobiles. Others are caused by hunter, hikers(徒步旅行者), fishermen, or woods workers who are careless in disposing of their smoking materials. The Forest Service has posted rules in many of the National Forest that prohibit smoking except in certain designated (指定的)areas. Many of the states have laws against throwing lighted materials from automobiles. The prevention of smoker-caused fires, however, depends upon changing the attitudes and behavior of millions of people who smoke in hazardous(危险
A. smoking in forests
B. changing the attitudes and behavior of millions of people
C. the chief causes of forest fires and their prevention
D. advances in knowledge of fire weather
Prolonging Human Life
Prolonging human life has increased the size of the human population. Many people alive today would have died of childhood diseases if they had been born 100 years ago. Because more people live longer, there are more people around at any given time. In fact, it is a decrease in death rates, not an increase in birthrates, that has led to the population explosion.
Prolonging human life has also increased the dependency load. In all societies, people who are disabled or too young or too old to work are dependent on the rest of society to provide for them. In hunting and gathering cultures, old people who could not keep up might be left behind to die. In times of famine, infants might be allowed to die because they could not survive if their parents starved, whereas if the parents survived they could have another child. In most contemporary societies, people feel a moral obligation to keep people alive whether they can work or not. We have
A. the need to prolong the lives of old people.
B. the need to enrich the life of the retired people.
C. the need to build profit-making nursing homes.
D. the need to take care of a sick and weak person.
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