正弦规是利用三角正弦计算原理制造成的测量角度或锥度用的精密量具。
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还要对贮藏的产品进行定期检查,了解产品的质量状况,做到心中有数,发现问题及时采取相应的解决措施。对于不耐贮的新鲜果蔬产品每间隔()检查一次,耐贮性好的可15d甚至更长时间检查一遍。
A. 2~4d
B. 4~6d
C. 5~7d
D. 3~5d
管道的螺纹连接,当介质的温度大于120摄氏度时,填料应选用聚四氟乙烯生料带。()
A. 正确
B. 错误
储集层的非均质性将()影响到储层中油、气、水的分布规律和油田开发效果的好坏。
A. 间接
B. 直接
C. 严重
D. 可能
You issue the following RMAN command to set a retention policy on a database: RMAN>CONFIGURE RETENTION POLICY TO REDUNDANCY 2; What will be the outcome of issuing this command?()
After two days,a backup will be marked obsolete
B. After two days,a backup will be deleted from the media
C. If the RMAN repository has records of two or more recent backups of a file,then older backups will be deleted from the media.
D. If the RMAN repository has records of two or more recent backups of a file then older backups will be marked obsolete.