For many ____ people thought, humans could fly ____ the birds. The famous ____ Leonardo da Vinci ____ this when he studied flight. He ____ machines with ____ that go up and down.Brothers Montgolfier made the first ____. Englishman Cayley designed gliders. One of them had a boat and ____. In 1903 the first plane travelled in the air. It had ____ and needed ____.

History of Flight 2

由
列印
嵌入

排行榜

視覺風格

選項

切換範本

恢復自動保存: ?