Ballpoint pens have made life easier for millions of people. At one time( 1)did not like their students writing with pens. The reason was( 2)pens can leak and it is very easy to spill the ink. Besides, it is very hard to write on( 3)or cheap paper with them. Ladislao Biro worked (4)a newspaper in Budapest. He spent all day at his desk. Day after day, he corrected pages of thin, cheap paper with a pen and ink. He often had to stop to(5)his pen with ink and it did not write well on the thin paper. He and his brother began some experiments. They wanted a pen that did not leak,with ink that did not spill. Why not( 6)a little ball at the end? Two Englishmen, Henry Martin and Frederick Miles, liked the (7). It was the time of the Second Word War. The Air Force( 8)a non-leak, non-spil pen for the men to write with in (9).Martin and Miles made and (10)thousands of Biro pens to the Air Force.