Spark plugs only ignite the fuel mixture near the spark gap, reducing the combustion efficiency, and the metal that makes them up is slowly eroded as they age.

火花塞只点燃火花隙附近的燃料混合物，这就降低了燃烧效率，并且随着使用年限增加火花塞中的金属慢慢被侵蚀。

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Some believe that the hardened gray iron used to make the components simply "fatigues" with age-as metal parts that go through millions of stress reversals eventually do.

有些人认为硬化的灰铸铁过去曾使零件很容易腐朽老化(因为经过数百万次的应力反向处理后的金属零件最后都会这样)。

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According to him, the main stages in human evolution are measured by the use and exploration of the Earth's resources by humans: the Stone age, Metal, Coal, Oil, etc.

根据他的说法，人类的进化阶段由人类利用和勘探的地球资源来划分：石器、铁器、煤炭、石油等等。

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The critically acclaimed first "Thief" game was followed by two sequels, 2000's "Thief II: The Metal Age" and 2004's "Thief: Deadly Shadows, " before the franchise faded from view.

NPR: 'Thief' Slithering Into Next Generation Of Games

Their music has encompassed genres ranging from heavy metal to new age.

CNN: It's not cool to like RUSH. That's OK

The disaster led the authorities to decide to mount the first lighthouse on Fastnet, one made of cast-iron, it being the metal of the age.

ECONOMIST: The Fastnet Lighthouse: Light on a lonely rock | The