the 18th and early 19th century中century为什么不需要复数

在北师大高中英语教程的模块二（Unit 5）的Styles of Music中有如此一段：

Classical music was the music of European courts and big concert halls. Specially, classical music refers to orchestral music of the 18thand early 19thcentury.

问题：名词 century 遭到 18th和 early 19th的修饰，它为何不需要复数呢？明明是指的两个两个世纪嘛！

你的句子中的 orchestral music of the 18th and early 19th century 其实是 orchestral music of the 18th century and the early 19th century 的省略形式，即是分别指 18 世纪和19世纪初。

类似的使用方法如：

1. She likes classical and country music. 她喜欢古典音乐和乡村音乐。

2. Road and bridge construction is underway.公路和桥梁正在建设中。

3. Drug and alcohol abuse contributed to Brian’s early death. 对药物和酒精的滥用致使了布赖恩的早亡。