Gears help them change speed — like on a bicycle. Switch gears. So is this a biking expression? Let's listen.

齿轮帮助他们改变速度——像自行车一样。所以这个一个自行车的表达吗？我们听一听。

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Single-speed cycles-that is bikes with no gears, are really only suited to short, casual rides.

单速自行车是指没有变速装置的自行车，只适合短途的休闲旅游。

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Gears change within milliseconds, without having to reduce speed, decrease engine power or use a clutch.

换档能够在毫秒级的时间内完成，无须减速，无须降低引擎动力，同样不需要使用把手。

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The eight-speed Tiptronic transmission slips through the gears seamlessly, with the center console-mounted gearshift providing sequential manual access to each cog.

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There's an automatic mode to BMW's SMG, and it happens to be a very pleasing system, with adjustable shift speed so you can dial in how smoothly gears change.

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Instead of stepped gears like a conventional transmission, it has a fixed planetary gear, and changes engine speed by adjusting the generator electric load.

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