nts grid errors, specific method is from baseline to methyl vertical box center line distance for a,, to b vertical box distance for b, list can measuredРРseveral group number, then with b ± a, =c,c is is methyl b two vertical box between of accurate size. Per-2~3 measurement, such as proceeds of c values are equal and equal to the design value, then the vertical installation accurate. For example a, b, and c valueswhile on horizontal vertical errors for measurement, General in iron angle code bit at measurement level points grid errors, specific method is from baseline to methyl vertical box center line distance for a,, to b vertical box distance for b, list can measuredР细小物,注意玩,千万别往口中含。水火电,莫乱玩,平安常识记心间。Р遇火灾,1 1 9,速离险境求援助。陌生人,莫轻信,防止坏人将你骗。Р遇匪徒,1 1 0,机智巧妙去周旋。雷电闪,不虚惊,避开高树地下蹲。Р地震时,莫慌张,紧急撤至空地上。