A. 正确 B. 错误
A. 查询 B. 管控 C. 跟踪 D. 统计
A. 测定天平的标牌分度值 B. 测定天平的空载示值变动性 C. 测定天平的全载示值变动性 D. 底脚螺纹是否保证天平放置平稳
A. by sight and hearing only B. by all available means besides sight and hearing C. by all available means except sight and hearing D. by none of above mea