1The definition of extreme sportsAn extreme sport(also called action sport and adventure sport)is a popular term for certain activities perceived as having a high level of inherent danger.These activities often involve speed,height,hight level of physical exertion,and hightly specialized gear or spectacular stunts.2ClassificationIn 2004, author Joe Tomlinson classified extreme sports into those that take place in air, land, and water.Nine air sports are mentioned including: base jumping, （定点或极限跳伞）bungee jumping, ski jumping（跳台滑雪）,hang gliding（滑翔式飞行）sky surfing（空中冲浪滑翔）sky flying（空中飞行） etc.Eighteen land sports including: adventure racing（冒险赛车）,ice climbing（攀登冰坡）, freestyle skiing（花样滑雪）, speed biking （变速自行车）etc.Fifteen water sports including: free-diving（自由潜水）, open water swimming（天然水域游泳）,scuba（戴水肺潜水）diving, windsurfing（帆板运动 ）etc.34NOW lets go to see some popular extreme sports Bungee jumping is an activity that involves jumping from a tall structure while connected to a large elastic cord. 5Jumpers stand at about 40 meters above the height of the tower crane, bridge, building, or even a hot air balloon,and the end is fixed by a long rubber strip(橡胶带) tied to the ankle, then outstretch arms, legs close together, head down to jump6蹦极之最蹦极之最 The worlds highest bungee jumping point is located at the American Royal Gorge Bridge(皇家峡谷悬索桥皇家峡谷悬索桥 )bugee jumping, 321 meters high.7Second high bungee jumping point is in Macao tower, 233 meters high 8The third tallest bungee jumping points is Swiss Verzasca(韦尔扎撕卡) dam bungee jumping, 220 meters high9Skateboarding 滑板运动Skateboard project is the historical founder of extreme sports, extreme sports are a number of projects extending from skateboarding. At the end of fifties and the early nineteen sixties，the Skateboarding evolved from surfing, and now has become one of the worlds most cool movement.g10Skateboarding is not to look cool。Skateboarding is a physical exercise, its very challenging 11Skateboarding day is on June 21st.If you are loyal to skateboarding molecules, so on this day on your board to celebrate the world on board.121314Skydiving 跳伞运动 Skydiving involves jumping from an aircraft with a parachute(降落伞） and performing acrobatics(杂技) in the free fall as long as possible before pulling the ripcord（降落伞的开伞索） and opening the parachute. 15Since the beginning of 20th Century, aircraft are widely used in aviation(航空） and military（军事） aspects, a parachute is practical for flight personnel life-saving appliances, and gradually developed into sports activities.16As a kind of extreme sports, from the towering buildings vertical（垂直面） and relatively dense（密度大的）city high jumping, limit skydiving does have the out of the ordinary wonderful place.17Parkour 跑酷 Parkour requires no specific 9)accessory for its practice.跑酷运动对装备没有什么特定的要求。 More recently Parkour can trace its roots to one George Hebert .最近跑可以追踪其根源之一乔治赫伯特。 Art of balance-The Professional Blog of slackline,climbing,parkour.平衡艺术-走扁带 Has unrivalled experience, rather than in the professional parkour in china.在中国有着无可匹敌的经验，与其在中国跑酷 的专业。 subway parkour18Parkour is an art that helps you pass any obstacle to go from point A to point B using only the abilities of the human body. It is meant to help one overcome obstacles, which can be anything in the surrounding environmentfrom branches and rocks to rails and concrete wallsand can be practiced in both rural and urban areas. 1920