The economic analysis of movable markstone and cement markstone is given.
最后对活动标石与水泥标石进行了经济分析。
2
The fabrication and installation of extension mark stones and detachable mark stones are presented. Finally, the economic analysis of movable markstone and cement markstone is given.
简介了伸缩型和分体型活动标石的制作及安装，最后对活动标石与水泥标石进行了经济分析。
3
He believes that as far back as 30,000 B.C., hunters may have used a system of notation, engraved on bone and stone, to mark phases of the Moon.