Geodetic leveling should be done with staves in which the onstrip of invar.大地水准测量必须使用分划刻在因瓦带上的水准标尺....

n.不胀钢...

invar的音标：invar的英式发音音标为：[ɪn'vɑ:]invar的美式发音音标为：[ɪn'vɑ]...