涡轮冷却原理是（）。

A.将增压气体膨胀和热能转变为机械能而达到冷却目的。

B.由冲压空气经过热交换器而使温度降低。

C.由涡轮将热空气吸入第二级热交换器而冷却。

D.涡轮的转动，能起到风扇的吹风作用，使空气冷却。

To be successful，the organization should be committed to addressing the management of risk______．

A．just before a meeting with a client

B．proactively and consistently throughout the project

C．as soon as time and cost estimates are ready

D．early in the execution phase