交流单相电力电缆的金属护层,必须直接接地,且在金属护层上任一点非接地处的正常感应电压,应符合()。
A. 未采取不能任意接触金属护层的安全措施时,不得大于50V
B. 未采取不能任意接触金属护层的安全措施时,不得大于60v
C. 已采取不能任意接触金属护层的安全措施时,不得大于100v
D. 已采取不能任意接触金属护层的安全措施时,不得大于120V
What are two reasons to create synonyms? ()
A. You have too many tables.
B. Your tables are too long.
C. Your tables have difficult names.
D. You want to work on your own tables.
E. You want to use another schema's tables.
F. You have too many columns in your tables.