Which three are valid？（） ["p0=p1；","p1=p2，","p2=p4；","p2=（ClassC）p1；","p1=（ClassB）p3；","p2=（ClassC）p4；"]
马斯洛需要层次论认为人类的基本需要包括（） ["生理需要","安全需要","爱和归属的需要","尊重的需要","自我实现的需要"]
天然气水化物形成的主要条件和解堵措施？
You would like to create an RMAN recover catalog in which to store information about your DB01 database. You want to use the database named RCDB for the storage of your recovery catalog. The six steps you will follow to create a recover catalog are not displayed in the correct order. Which displays the correct order？（） 1. Grant the appropriate privileges （CONNECT and RESOURCE） and roles （RECOVERY_CATALOG_OWNER） to the user responsible for performing backup and recover operations. 2. Register the target database in the catalog. 3. Create the catalog using the RMAN command line interpreter. 4. Create a user and schema which will own the recovery catalog. 5. Create tablespace to hold the catalog in the database you have dedicated for your RMAN recovery catalog. 6. Connect to the target database using SYSDBA privileges. ["4，1，5，6，3，2","4，3，1，5，6，2","4，5，1，3，2，6","5，4，1，3，2，6","5，4，1，3，6，2"]
世界公认最早的太阳黑子记录出于（）。 ["《周易》","《汉书·五行志》","《史记·天官书》","《灵宪》"]
软件定义时期主要包括（）和（）两个阶段。
