You want to analyze a SQL Tuning Set （STS） using SQL Performance Analyzer in a test database. Which two statements are true regarding the activities performed during the test execution of SQLs in a SQL Tuning Set？（） [" Every SQL statement in the STS is considered only once for execution."," The SQL statements in the STS are executed concurrently to produce the execution plan and execution statistics."," The execution plan and execution statistics are computed for each SQL statement in the STS. "," The effects of DDL and DML are considered to produce the execution plan and execution statistics."]
MD5算法是一个在电子商务中广泛应用的（） ["对称加密算法","公开密钥算法","散列算法","私有密钥算法"]
不得从事液化石油气充装的人员是（）。 ["充装员","检查员","站长","技术负责人"]
资格预审申请文件格式中，“申请人基本情况表”、“原件的复印件”要求申请人如实反映申请人资质条件，申请人应按照要求（）资质等级证书副本复印件，有原件要求的提交原件。 ["填写","提交","填写或者提交","填写并提交"]
The CUSTOMERS table has these columns: The CUSTOMER_ID column is the primary key for the table.Which two statements find the number of customers? （） [" SELECT TOTAL(*) FROM customers;"," SELECT COUNT(*) FROM customers;"," SELECT TOTAL(customer_id) FROM customers;"," SELECT COUNT(customer_id) FROM customers;"," SELECT COUNT(customers) FROM customers;"," SELECT TOTAL(customer_name) FROM customer"]
简论教育社会学研究的客观性。
