One way to increase the efficiency of a high-bypass jet engine is to turn the fan into an open rotor, a bit like returning to propellers, but using two rings of stubby counter-rotating blades.

提高高旁通飞机引擎的方法之一就是把风扇变成开放式旋翼，有点回归于螺旋桨的味道，但要使用两圈粗短的反旋桨叶。

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Using intelligent digital counter, convenient and quick to improve production efficiency.

采用智能数显计数器，方便快捷提高生产效率。

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At present, the main method of testing air filters is fraction efficiency testing method with particle counter.

以粒子计数器为测试手段的粒径效率测试法是目前过滤器测试的主要方法。

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However, senior Labour figures north of the Border counter that more people are being treated and the government is progressing with its NHS efficiency drive and will continue to do so if it earns a second term.

BBC: Tempers rise over health figures