想問下單數同眾數問題...

重點在於traffic呢個字
查一查yahoo字典:
n.[U]交通There is too much traffic on the road.這條路上行人車輛太多了。Police control the traffic in large cities.在大城市裡, 警察控制交通。交通行列; 交通量Traffic is very heavy during the rush hour.尖峰時間交通十分繁忙。貿易, 買賣; 非法交易[(+in)]Illegal traffic in protected animals is quite common there.非法買賣受保護的動物在那裡是司空見慣的事。運輸; 運載量; 運輸業Passenger traffic has gone up by 20 per cent.客流量已增長百分之二十。交往, 交流I don't want any more traffic with his sort.我不想再和他那種人來往了。電信; 電信業務Radio traffic has stepped up enormously.無線電通訊已大大增加。
traffic當作名詞用果陣係[U],代表uncountable
好似water,money等詞語,基本使用時都係uncountable,應視為單數,亦唔會+s
所以係用was唔係were

Since traffic is clarified as a system of transportation facilities, cars, railways, ships, planes,etc, which means traffic can only be used as a singular thing since we just take the whole case as one system.

it should not able to use 'were' otherwise will fail
the word 'traffice' is uncountable,and only for singular
that's it

"traffic" is not countable
so it is singular

we use ' is , was ' instead of ' are, were ' for singular noun