万神殿的正面有个方尖碑.Right in front of the Pantheon, there is an obelisk.这广场上有3座喷泉和1个方尖碑.At the plaza, an obelisk and 3 fountains.接著,他向左转身,沿著铜线向北面的方尖碑走去.Then he turned left and followed the brass line due north toward the obelisk...
下列插图是一些常见的杠杆和压铁位置.Illustrated below are some commonly accepted positions of the lever and weight.安装杠杆和压铁有助于阀瓣的关闭.Lever and weight mounted to assist the disc in closing.配置杠杆和压铁是为了在外部控制阀瓣运动.The lever and weight arrangement...