As one of these components, friction modifier plays an important function for removing the dirt and coloredsubstance attached to the surface of tooth.
磨擦剂作为牙膏的组分之一，在其中起着重要的作用，它能有效的除去附着在牙齿表面的污垢和有色物质。
2
The rats used in the tunnel scene were specially-trained and colored with a dark, charcoal-like substance to give them the appearance of wild, dirty tunnel rats.
Visually enchanting, Mirror Mirror is an example of style over substance, of the use of brightly colored costumes and fantastical sets to distract viewers rather than enhance the story.