There have been many great inventions or things that change the way we live. The frst great invention is the one that is still very important today一the wheel. This makes it easier to carry heavy things and to travel long distances.
For hundreds of years after that there were few inventions that as much effect as the wheel. Then in the early 1800s the world started to change. There was little unknown land left in the world. People didn't have to explore much anymore. They began to work in order to make life better.
In the second half of the 19th century, many great inventions were made. Among them were the camera, the light and the radio. These all play a big part in our daily life today.
The first part of the 20th century saw more great inventions. The helicopter in 1909, movies with sound in 1926, the computer in 1928, jet planes in 1930. It was also a time when a new material was first made Nylon (尼龙), which came out in 1935. It changed the kind of clothes people wore.
The middle part of the 20th century brought new ways to help people get over diseases. They worked very well. They made people healthier and allowed them to live longer. By the 1960s most people could expect to live to be at least 60.
By this time most people in developed countries had a very good life. Of course new inventions continued to be made. But man now had a desire (渴望) to explore again. The Earth was known to man but stars were not. Man began looking for ways to go into space. Russia, United States, China and Japan have made their own steps into space.
In 1969, man took his biggest step away from the Earth. Americans first walked on the Moon. This is certainly just a beginning, though. New inventions will some day allow us to do things we have never yet dreamed of.
