—Mum, may I go to the cinema?  

—No, you ____. You ____ finish your work first. [ ]

A. can't; can

B. may not; may

C. can't; must

D. mustn't; might

在衡量产品项目质量的指标中，( )是指产品的主要特征。

A．性能
B．可靠性
C．特点
D．一致性