B
Famous Inventions
There are millions of famous inventions. Some of them are still useful today, like the invention of light bulb（灯泡），colour television and computer.
Light bulb is a useful invention. In the early days, people used gas lamp to give light. But it was very dangerous. After trying many times, Thomas Edison finally invented a light bulb. It could light for 1,200 hours. Today, we are still using it.
Another famous invention is the computer. In the last 50 years, no inventions have changed our lives more than the computer. In 1941, a German called Konrad Zuse invented the first computer. In 1944, two inventors made a bigger and better computer. It weighed（重）as much as an elephant. After 1947, people invented the transistor（晶体管）and microprocessors（微处理器）. Computers would not be big and heavy anymore. Today, computers are easy to carry and use.
Every great invention needs years of improvements（改善）to get better. What would your life be like without these inventions?
