________ the working efficiency, the boss allows the employees to have a coffee break.    [ ]

A. Improving

B. To improve

C. Having improved

D. Improved

下列软件缺陷中， ______是活动状态， ______是非活动状态。

A．打开和解决；关闭
B．打开；解决和关闭
C．通过；失败
D．打开；待验和关闭