—Why didn't you answer my phone when I phoned you at about 11 p. m. yesterday?

—I ___________and failed to hear the phone.

A．might have slept

B．must be sleeping

C．might be sleeping

D．must have been sleeping

我们一定要让企业和群众更多感受到（）改革成效，着力打通“最后一公里”，坚决除烦苛之弊、施公平之策、开便利之门。