Health is something we tend to (1) _____ when we have it. When our body is doing well, we are hardly (2) _____ of it. But illness can come, even (3) ____ we are young. In fact, childhood has been a very susceptible time. Many diseases attack children in particular, and people know very little (4) ___ to cure them once they struck. The result was that many children died. About a century ago,(5) ______, scientists found out about germs, and then everything changed. The (6) _____ of many diseases was found, and cures were developed. As this medical discovery spread, the world became(7) ____ safer for children. The result is that (8) _____ a hundred years ago, the average man lived for 35 years, nowadays, in many areas of the world, people can (9) _____ to live for 75 years. And what do we expect by the year 2020 ? Undoubtedly, medical science will continue to (10) ________. Some people will be able to avoid medical problems that are unavoidable today.