synthetic dye的用法和样例：
例句
- Indelible ink often consists entirely of synthetic dyes.
不褪色墨水一般均由合成染料构成。 - Natural dye extracts, however, are just as quick to use as synthetics but produce the genuine natural colours of real natural dyes.
然而，天然染料，也像合成染料一样正被人们更多的接收和使用，但是只有天然染料才能产生真正逼真的颜色。
