要反映滨州1—7月份的气温变化情况，选择哪种统计图比较合适？[ ]
A．条形
B．折线
C．扇形
答案：B
Which values are not permitted to be part of the primary key ( )
A．alpha-numeric characters
B．punctuation
C．special characters
D．NULL
订房员在订房时一定要问清（）个要点并及时记入表格内。
A.10
B.15
C.13
D.12
