Which two statements are true regarding listeners（） Listeners use only the TCP/IP protocol.。 Multiple listener processes can run simultaneously on a host.。 Multiple database instances can be registered with a single listener.。 The listener-related errors can be traced only at the administrative level.。 Only one database instance can be registered with a single listener at any time.。
抗生素是如何杀菌和抑菌的？
Which two of statements are true？（） It is possible to synchronize static methods.。 When a thread has yielded as a result of yield（）， it releases its locks.。 When a thread is sleeping as a result of sleep（）， it releases its locks.。 The Object.wait（） method can be invoked only from a synchronized context.。 The Thread.sleep（） method can be invoked only from a synchronized context.。 When the thread scheduler receives a notify（） request， and notifies a thread， that thread immediately releases its lock.。
Which naming method uses the tnsnames.ora file to store the connect descriptor used by the client while connecting to the database instance from a remote machine？（） host naming method。 local naming method。 external naming method。 directory naming method。
Which naming method uses the tnsnames.ora file to store the connect descriptor used by the client while connecting to the database instance from a remote machine（） host naming method。 local naming method。 external naming method。 directory naming method。
在污水处理设备中，往经过分离槽的污水中加凝聚剂的应是：（）
