LONGER LIFESPAN It's amazing how much society has changed over time. Just a hundred years ago, people's lifestyles were much different from how they are today. It's not just the way we live our lives (3) has changed, but the length of our lives has amazingly increased over time as well. Believe it or not, in the year 1900, the (4) human being only lived for around 35 years. Since then, that number has jumped to over 70, meaning it has doubled in a little more than a century! So, what is behind this amazing change? Well, the 20th century was a very important turning point for science, and a lot of important developments happened. During this time, doctors and scientists put an end to a lot of major diseases, such as smallpox and polio. They learned more about how diseases and infections spread and created medicines that helped us prevent them. Public healthcare has (5) too. Thanks to technology, it's now possible to get life-saving operations that didn't exist before. This also helped to increase life expectancy. The other big factor is how we eat. Since 1900, we have learned a lot about what we need from our food. (6) we have developed ways to grow the right foods to keep us healthy, which helps us to grow stronger and live longer. The life of a human being is different in so (7) ways from how it was just a century ago, and we should be thankful to modern science. It's exciting to think about what life will be like 100 years from now!