有强烈蓝色荧光的香豆素类化合物是（） 简单香豆素。 7－OH香豆素。 8－OH香豆素。 8－OCH3香豆素。
顾客评价产品和服务的依据主要有（） 搜寻特性。 评价特性。 经验特性。 了解特性。 信任特性。
Which two statements are true about WHERE and HAVING clauses? （） A WHERE clause can be used to restrict both rows and groups.。 A WHERE clause can be used to restrict rows only.。 A HAVING clause can be used to restrict both rows and groups.。 A HAVING clause can be used to restrict groups only.。 A WHERE clause CANNOT be used in a query if the query uses a HAVING clause.。 A HAVING clause CANNOT be used in subqueries.。
下列产品哪些是附有有形产品的服务（） 航空客运。 食盐。 宾馆。 心理咨询。 计算机。
You have used the CROSSCHECK BACKUP command to verify that the backups recorded in the RMAN repository actually exist. Which command should you now use to check if any of the files were missing？（） LIST EXPIRED。 DELETE EXPIRED。 DELETE OBSOLETE。 CHANGE UNCATALOG。
服务质量构成要素包括（）
