The regenerative indirect evaporative cooling with the positive feedback principle, can further decrease the temperature of the prime air stream and expand the usefulrange of available energy.
回热式间接蒸发冷却具有正反馈式工作原理，能进一步降低一次空气温度，扩大有用能的利用范围。
2
These components can do a range of small, useful, flexible operations between a consumer and a service provider.
这些组件可以完成一组消费者和服务提供者之间细小、有用、灵活的操作。
3
These tools were useful for a wider range of tasks than the Oldowan ones.