IT服务计费的前提是（） 管理层要求对提供IT服务的成本进行控制。 服务提供方要求作为业务单位运营。 IT服务的计费原则和计费方法已经确定。 已掌握了实际的IT服务运营成本。
对输送天然气管线进行压力试验时，一般选用的试验介质为（） 氮气。 空气。 天然气。 氩气。
Given: When line 15 is reached, how many objects are eligible for the garbage collector?（） 0。 1。 2。 3。 4。 5。
Twenty database users are connected to your database. Five of the users are running long queries involving sort operations. The TEMP tablespace is the default temporary tablespace for your database. You are performing offline tablespace backups of individual tablespaces and erroneously execute the following statement： SQL>ALTER TABLSPACE temp OFFLINE NORMAL； What is the result of this statement？（） The TEMP tablespace is taken offline. The users using the TEMP tablespace for sorting are disconnected after their queries complete.。 The TEMP tablespace is taken offline. The users using the TEMP tablespace for sorting are disconnected and must re-execute their queries.。 The TEMP tablespace is taken offline. The users using the TEMP tablespace for sorting are not disconnected， but these users must re-execute their queries.。 The TEMP tablespace is not taken offline. The users using the TEMP tablespace for sorting are not disconnected， and their queries execute successfully.。
往复式压缩机与离心式压缩机相比，转速（），结构复杂，日常维修量大，动平衡性差，排气（）。
关于施工成本管理措施，正确的有（）。
