冷冻封堵作业选用（）进行封堵。 液氮。 液氨。 水。 冰。
You are managing the APPPROD database as a DBA which is not using the Oracle-managed files. You plan to duplicate this database in the same system with the name DUPDB.You want to create the same directory structure for duplicate database files as of the target database. You executed the following RMAN commands: What are the implications of this command?（） It creates database files for the duplicate database under the Oracle base with a different directory for the duplicate database.。 It overwrites data files of the target database because a different location for data files is not mentioned for the duplicate database.。 It creates database files for the duplicate database under the same Oracle home as that of the target database with the same directory structure.。 It creates database files for the duplicate database under the same Oracle home as that of the target but with a different directory for the duplicate database.。
试述影响食品安全性评价的因素。
研磨剂中的磨料，微粉用混沉法取得，号数越大，磨料越粗；号数越小，磨料越细。
以下关于食品的低温储存技术的论述，正确的是（） 冷却法适用于水分含量较高的生鲜食品。 -2℃～2℃是果蔬的储藏温度。 使用冷冻法储藏食品时，其温度控制在0℃～10℃。 低温储存技术是利用低温降低氧气浓度抑制霉腐微生物的生理活动。
Given:
Which code, inserted at line 15, creates an instance of the Point class defined in Line?（）
