英语语法分析

The blue dye is obtained from the indigo plant.

蓝色染料是从靛蓝植物中提取的。

The blue vat dye obtained until about 1900 entirely from some species of the indigo plant.

直到大约1900年，蓝色还原染料都是从靛蓝植物中提取的。

The indigo plant was highly valued until the discovery of chemical dyes in the 19th century.

在19世纪发现化学染料之前，靛蓝一直被高度重视。