某学生用量筒量取液体，量筒摆放平稳，且学生面对刻度，他首先俯视凹液面的最低处读数为19mL，倾出一部分液体后，又仰视读数为10mL,则该同学实际倒出液体的体积为（    ）

A．等于9mL

B．大于9mL

C．小于9mL

D．无法确定

Bill's aim is to inform the viewers that cigarette advertising on TV is illegal, ______? [ ]

A. isn't it

B. is it

C. isn't be

D. is he