Roof racks increase the car's weight and reduce aerodynamic efficiency, which increases the amount of fuel burnt to power the car.

行李架增加车子的重量，降低空气动力学功效，那会增加车辆燃烧的燃料量。

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The maximum amount of increasing in weight of steel is 22%for the roof purlins.

用钢量增加幅度最大的是不上人的轻型屋面檩条，提高幅度达22%。

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Roof is composed of heterogeneous rock. When roof failure happens, a large amount of energy would release in the form of seismic wave.

顶板是一种典型非均质岩石材料，在其破坏演化过程中将释放能量产生地震波。

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So is an electrotransparent glass roof that allows passengers to control the amount of sunlight entering the cabin during the day, or, at night, to adjust the ambient lighting.

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One of the most arduous undertakings was to raise the roof 20 inches a seemingly small amount, but enough to dramatically open up the view of the water from a long upstairs balcony.

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"If we can secure this final amount then work can start on the roof in two months, " he said.

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