The shadoof was invented in China sometime between 770 BC-476 BC.

在機械原理一本到高清久久婷婷国产、結(jié)構(gòu)設(shè)計和動力應(yīng)用等方面都取得較高成就。

"As early as 1500 BC people were raising water and lifting soldiers over battlements using the swape or shadoof, a long lever pivoted near one end with a platform or container hanging from the short arm and counterweights attached to the long arm."

早在公元前1500年，人們就利用汲水吊桿的裝置來提水或吊送士兵過戰(zhàn)壕。這種裝置是一根長的杠桿人人人人操人人操，支點靠近一端，短臂上掛一個平臺或容器网色网站大全cao，與之平衡的重物綁在長臂上国产熟女网站。

"As early as 1500 BC people were raising water and lift ing soldiers over battlements using the swape or shadoof, a long lever pivoted near one end with a platform or container hanging from the short arm and counterweights attached to the long arm."

早在公元前1500年，人們就利用汲水吊桿的裝置來提水或吊送士兵過戰(zhàn)壕一区二区三区不卡高清视频。這種裝置是一根長的杠桿www。色色色色，支點靠近一端，短臂上掛一個平臺或容器91看黄片，與之平衡的重物綁在長臂上。

"As early as 1500 BC people were raising water and lifting soldiers over battlement s using the swape or shadoof, a long lever pivoted near one end with a platform or container hanging from the short arm and counterweights attached to the long arm."

早在公元前1500年午夜理论片2018理论中字，人們就利用汲水吊桿的裝置來提水或吊送士兵過戰(zhàn)壕国产爱福利。這種裝置是一根長的杠桿，支點靠近一端初高中生黄福利网站，短臂上掛一個平臺或容器国产在线A级视频，與之平衡的重物綁在長臂上。

"As early as 1500 BC people were raising water and lifting soldiers over battlements using the swape or shadoof, a long lever pivoted near one end with a platform or container hang ing from the short arm and counterweights attached to the long arm."

早在公元前1500年H无码精品动漫在线观看,免费A级毛片无码，人們就利用汲水吊桿的裝置來提水或吊送士兵過戰(zhàn)壕欧美18性欧美在线。這種裝置是一根長的杠桿，支點靠近一端精品人妻色导航，短臂上掛一個平臺或容器亚洲中文久久精品无码性色av，與之平衡的重物綁在長臂上。