Phenolphthalein or indicator of such a kind is used as colour indicator.

本发明还可加入酚酞或酚酞类酸碱指示剂作显色指示。

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Not confined to clothing, silk was also used for a number of other applications, including writing, and the colour of silk worn was an important indicator of social class during the Tang Dynasty.

丝绸不仅用于衣物，而且还有许多其它用处，包括书写，以及人们穿戴丝绸的颜色在唐朝是社会阶级的重要标志。

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Simultaneously, the challenge of dividing the required functions within the spa was just as important, using colour as an indicator of program.

将各种需要的功能空间规划放置在这个狭小的空间里的挑战，一点都不比使用色彩做为空间的引导和划分来得容易。

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Their reasons for doing so seem to be that the depth of the colour is a good indicator of how free a male is of parasitic infection, and thus how good a father he will make.

ECONOMIST: Birds do it, bees do it | The