单项选择题
A. 2
B. 3
C. 5
D. 7
E. 9
单项选择题 How many students are either juniors or males or both（）
单项选择题 The water level in a tank is lowered by 6 inches, then raised by inches, and then lowered by 4 inches. If the water level was x inches before the changes in level, which of the following represents the water level, in inches, after the changes（）
