heavy traffic n.繁重交通;繁忙运输不可数的。He was late owing to/due to the very heavy traffic.他迟到是因为交通拥挤。His lateness was due to the very heavy traffic on the motorway.他迟到是因高速公路上车辆过多所致。Heavy traffic poses a problem in many old towns.交通拥挤是许多旧城镇的难题。What heavy traffic!多拥挤的交通!The heavy traffic crawled through the narrow tunnel.拥挤的车辆慢吞吞地穿过狭窄的隧道。
你在上文里提出过的话就要。There are heavy traffic on the road. "The" heavy traffic is caused by a accident ahead.可以。有帮助请采纳,所以不能加a,因为traffic是不可数名词不需要要的要因为这是特定名词The traciffic was really heavy, and the heavy tracffic caused a traffic jam.