Use premium fuel: If it is not possible to change the type of fuel your car can run on to bio, purchase the more expensive but environmentally friendly premium petrols.

选用质优价高的燃料：要是让你的汽车改用生物油不可行，就购买贵一点但是有利于环境的质优价高的燃料。

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Some environmentally-friendly cars are really expensive.

一些环保汽车十分贵。

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That makes traditional lighting expensive and environmentally hazardous.

这就使传统的照明方式昂贵而且对环境有害。

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But some warn the plan is environmentally risky and expensive.

VOA: standard.2009.08.01

Simply put, Millennials are driving less because they think car ownership is expensive and environmentally undesirable.

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"To lock ourselves into this 25-year project could be very expensive and environmentally very damaging, " added Mr Horwood.

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While grid operators have developed elaborate operating protocols to manage ramping events, they are almost always either expensive or environmentally problematic.

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