※ 글의 내용과 일치하지 않는 것을 고르시오. [문 17 ～ 문 18] The invention of the ski has contributed greatly to society. Unlike today, early skis were not used for fun but for transportation. They were made of wood and were not designed for speed. They were simply used to help a person to walk on the snow. However, it is not clear when they were invented. The world's oldest ski was discovered in Sweden in 1924. It is 80 inches long and 6 inches wide, that is, a little longer than and twice as wide as modern skis.