【单选题】已知"借阅"表中有"借阅编号"、"学号"和"借阅图书编号"等字段,每名学生每借阅一本书生成一条记录,要求按学生学号统计出每名学生的借阅次数,下列 SQL 语句中,正确的是
A.
SELECT 学号, COUNT( 学号 ) FROM 借阅
B.
SELECT 学号, COUNT( 学号 ) FROM 借阅 GROUP BY 学号
C.
SELECT 学号, SUM( 学号 ) FROM 借阅
D.
SELECT 学号, SUM( 学号 ) FROM 借阅 ORDER BY 学号
【判断题】对于共阳极结构的显示译码器,当某一字段发光二极管的阴极为低电平时,相应字段就点亮。( )
【简答题】Total absoption cost of sales
【单选题】Christopher bought 4 cans of soup for a total of $3.36,which included sales tax of $0.16. At the same per-can cost, what is the cost before the sales tax is added for 6 cans of the same soup?
【多选题】关于widget(组件)属性的写法,下面哪个是正确的?()
A.
android:id=”@+id/tv_username”
B.
android:layout_width=”100px”
C.
android:src=”@drawable/icon”
D.
android:id='@id/tabhost'