A.圓水準(zhǔn)器B.水準(zhǔn)尺分劃C.水準(zhǔn)尺是否彎曲D.水準(zhǔn)尺名義長(zhǎng)度
A.53.6B.46.6C.58.8D.63.5
A.8B.10C.12D.15