What does it mean if a backup is expired？（） [" The backup set has exceeded the retention criteria set in RMAN and is eligible for removal. "," The backup set has one or more invalid blocks in it and is not usable for recovery."," The backup set contains one or more tablespaces no longer in the database."," The backup set contains one or more missing backup set pieces."," The backup set is from a previous version of RMAN and was not upgraded."]
古罗马时代文化课程中的三艺是指（） ["几何、数学、天文","文法、修辞、辩证法","语文、数学、外语","文法、数学、辩证法"]
四环素抑菌的作用机制是（） ["抑制细胞壁合成","干扰细胞膜的功能","抑制蛋白质合成","抑制DNA复制"]
社会资本
A customer wants to expand their current storage environment, but has floor space for only two machine frames or two racks. Their environment consists of IBM SAN Volume Controllers and IBM DS4000 systems. The DS4000 systems are at end of lease. The customer wants the maximum number of disks possible in two frames. Which of the following solutions is best for this customer?（） [" add one SVC"," install one DS8700"," install one DS8800"," install one XIV system"]
试述怎样进行亚慢性和慢性毒性作用评价？
