单项选择题 How many students are either juniors or males or both（）

单项选择题 If the radius of a circular region were decreased by 20 percent, the area of the circular region would decrease by what percent（）

单项选择题 The median salary for professional group A is $40,610. The median salary for professsional group Bis $40,810. The median salary for groups A and $ 40,710 B combined（）