北宋文学家欧阳修，字永叔，号醉翁，晚年又号（）。
参考答案：六一居士
把6-（+3）-（-7）+（-2）写成省略括号的形式应是（ ）
A.-6-3+7-2 B.6-3-7-2 C.6-3+7-2 D.6+3-7-2
Security cameras are restricted to ________ spaces，such as hallways and exits.There will be no cameras in classrooms，locker rooms(更衣室)or bathrooms.
A．common
B．private
C．usual
D．ordinary
