The word health can be used in a number of ways. In the past, health meant only the absence of disease or illness, Today, though, health has a broader meaning. Health is the state of your wellbeing that includes how you feel physically, mentally, and socially. Well- ness is another term that describes this broader view of health. You can understand the need for a broader definition if you think about how health in your life is different from health in your grandparents' lives. In 1900, the main causes of death were diseases that were spread by bacteria (细菌) and viruses (病毒). If you had lived then, the danger of your dying from pneumonia (肺炎) would have been three times greater than the danger of your dying from cancer. The diseases that were most common in 1900 affected people of all ages. It is not surprising, then that around 1900, the emphasis of health was on freedom from illness. Today many of the diseases that were common in 1900 can be prevented or cured by improved medicines and methods of sanitation (卫生). Most diseases now are likely to occur later in life. You as a teenager will probably not have to think about the same threats to your health as your grandparents did. These improvements in health conditions mean that not only can you now enjoy a better life, but you also have a greater chance of having a longer life. Controlling diseases has increased the life expectancy in the United States. Generally, people born more recently have higher life expectancies. Since 1900, the life expectancy in the United States has increased by more than 27 years. It has increased from 47 years for those born in 1900 to 74 years 1981. According to Paragraph 1, health and wellness ______.