Nobody knows who invented the pencil or when it was invented. A Swiss  described a pencil in a book in 1565. He said it was a piece of wood with lead inside it . Pencils weren't popular, and people continued to write with pens. In 1795,someone started making pencils from graphite  and they became very popular. Today, people make pencils in the same way. They make the graphite into the shape of a stick, and then they put it inside a piece of wood. One pencil can make a line as long as 55 kilometers. When people first wrote with pens , they had to put the penpoint into ink after every few letters. Later someone invented a fountain pen  and this kind of pen could hold ink inside. A fountain pen can write several pages before you have to fill it again. Two brothers, Ladislao and Georg Biro, invented the ballpoint pen that we use today. They left their country Hungary and started producing ballpoint pens in England in 1943 during World War II. Later, a French company called Bic bought the Biro's company. Someone calls ballpoint pens bics. Australians call them biros. Whatever we call them, we use them every day. What is the passage mainly about?
Some famous inventors. The invention of some kinds of pens. Who invented the pencil Which kind of pen is the most useful.