What's the requirement for the forced ventilation system for crankcase? 发动机曲轴箱强制通风的要求？
All automobile engines now built are equipped with the positive-crankcase ventilation system of crankcase emission control. 所有现代制造的汽车发动机，都需要装备控制曲轴箱有害污染的曲轴箱强制通风系统。
Forced air systems send heated air through ductwork. 机械通风通过管道系统来输送热空气。
The building uses a mixed system of mechanical and natural ventilation, a high performance glass facade and other environmentally sustainable systems, such as sea water cooling. 建筑使用了机械通风与自然通风相结合的混合通风系统，高性能的玻璃立面，以及其他可持续系统如海水冷却系统。
