货运比例
货运比例-
在中国内地直接出口的货物中，航空货运的比例日益增加，不仅对航空公司造成影响，还令新加坡和香港等航空货运中心感到忧虑。
The growing proportion of air freight exported directly from the Chinese mainland is not only having an effect on the carriers , it is also worrying for cargo airport hubs such as Singapore and Hong Kong .
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模拟结果表明，货运车辆会对高速公路交通流产生扰动作用，影响行车安全：随着货运车辆比例增大，交通流平均速度减小，换道率和事故率上升。
The result shows that freight vehicles can interfere traffic flow on freeways and impose threat on road safety : while the proportion of freight vehicles increases , the mean running speed decreases ; however , the lane changing rate and accident rate go upward .