“Whycouldn’ttheymeetusatfiveo’clock?” “Becausetheyweredelayedby___

“Why couldn’t they meet us at five o’clock?” “Because they were delayed by ________.”A.heavy traffic　B.heavy trafficsC.crowded trafficD.crowded traffics

A解析对于此题，首先要明确traffic为不可数名词，没有复数形式，故排除B和D。另外，汉语习惯说“交通拥挤”，而英语习惯上却不能用crowded 来修饰 traffic，要表示汉语的“交通拥挤”，英语通常说heavy traffic，即选A。

这下我知道了