综合一区欧美国产,99国产麻豆免费精品,九九精品黄色录像,亚洲激情青青草,久久亚洲熟妇熟,中文字幕av在线播放,国产一区二区卡,九九久久国产精品,久久精品视频免费

Chinadaily.com.cn sharing the Olympic spirit
OLYMPICS/ Summer sports


Trampoline

Updated: 2006-08-19 15:16

 

 trampoline



There are two types of trampoline, recreational and competitive.

Recreational trampolines are less sturdily constructed and their springs are less strong. They may be of various shapes, though the most usual are circular, octagonal or rectangular. The fabric is usually a waterproof canvas or woven Polypropylene material.

The frame of a competitive trampoline is made of steel and can be made to fold up for transportation to competition venues. The trampoline bed is rectangular 428 cm (approx. 14 feet) by 214 cm (approx. 7 feet) in size[1] fitted into the 520cm x 305cm (17' x 10') frame with around 110 steel springs (actual number may vary by manufacturer). The bed is made of a strong fabric. The fabric can be woven from webbing which is the most commonly used material. However, in the 2007 World Championships to be held in Quebec City a Ross (or "Two-String") bed, woven from individual thin strings, will be used.

In any trampoline, the fabric bed is not elastic itself, the elasticity is provided only by the springs.

 

Comments of the article(total ) Print This Article E-mail
PHOTO GALLERY
PHOTO COUNTDOWN
MOST VIEWED
OLYMPIAN DATABASE
山东| 扎鲁特旗| 乐平市| 亳州市| 曲阜市| 个旧市| 灵寿县| 阿拉善右旗| 舞阳县| 营山县| 龙江县| 尚义县| 曲松县| 鸡西市| 巨野县| 商洛市| 定远县| 任丘市| 北流市| 得荣县| 山西省| 临澧县| 怀集县| 西平县| 莱州市| 德庆县| 樟树市| 平利县| 望城县| 鄂尔多斯市| 深水埗区| 黄梅县| 伊通| 抚松县| 祁东县| 廊坊市| 任丘市| 盐源县| 青冈县| 津南区| 古蔺县|