The children, _____ had played the whole day long, were worn out.

A．all of what

B．all of them

C．all of whom

D．all of which

把燃气轮机联合循环看成简单布雷登理想循环过程。压气机为（），燃烧室内为（）过程，透平为（），排气系统为（）过程。