英语作文：What is the greatest invention in the last century?

What is the greatest invention in the last century
We knew there had been many inventions at the last century, for example, electric light bulb, telephone, phonograph, mimeograph machine, automobile, airplane, atomic weapon, computer and so on. What’s the greatest invention in the last century?
Personally, I think the greatest invention should be computer.
Human being have been in possession of brightness since electric lamp was invented. With invention of the telephone in 1876, the people who live in eastern hemisphere and in the western hemisphere seemed nearer and nearer to live. But, with the occurrence of atomic weapon, there are many performances of tragedy, the disaster have even stayed to the contemporaries.
In the old days, many scientists took much time to calculate and deal with research data, so the effective time in doing research was relatively shortened. For millions of times of calculating per second by computer, the researchers may have enough time to study more important issues. The processing of experiment results became very simple and easy. Aren’t those all evidences that the computer is one of the greatest inventions in the last century, are those?
In one word, that the greatest invention is computer is not paint the devil blacker than it is.
备注：属于自己即兴写作.