Other birds have spread quickly across areas with heavy air traffic.

VOA: special.2009.04.01

And the traffic was really, really heavy.

那时，交通非常非常拥堵。

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Switzer says that the industrial nature of gas drilling, with heavy truck traffic and noise, and occasional wastewater and chemical spills,has transformed their peaceful country life.

VOA: standard.2010.01.02

Traffic is heavy along Maryland's Rockville Pike, outside Washington,DC.

VOA: standard.2009.12.20