听力原文:What kinds of businesses sometimes have small staffs? What are two kinds of businesses that sometimes have small staffs? ______ or manufacturer's representatives.
【判断题】查询平均成绩大于等于 60 分的同学的学生编号和学生姓名和平均成绩select t1.sid, t1.sname, t2.avgscorefrom student as t1 inner join (select sc.sid, avg(sc.score) as avgscore from sc group by sc.sidhaving avgscore >= 60) as t2 on t1.s...