Which two statements complete a transaction? （） ["DELETE employees;","DESCRIBE employees;","ROLLBACK TO SAVEPOINT C;","GRANT SELECT ON employees TO SCOTT;","ALTER TABLE employees SET UNUSED COLUMN sal;","SELECT MAX(sal) FROM employees WHERE department_id = 20"]
从固体废物中提取物质作为原材料或者燃料的活动是指固体废物的（） ["储存","利用","处置","处理"]
给下面的语言单位注音，指出其中的音变现象。
不肯
出现言语性幻听最常见的疾病是（） ["神经官能症","癔症","精神分裂症","神经衰弱","酒中毒"]
国民革命失败后，毛泽东在八七会议上提出的著名论断是（）。 ["须知政权是由枪杆子中取得的","兵民是胜利之本","一切反动派都是纸老虎","星星之火，可以燎原"]
最大爬坡度
