0 a chemical solution made from a mixture of substances that produce many different colour changes according to different pH levels, used to discover how acid or alkaline something is -- （化學上用的）通用指示劑（用來測定物質的酸鹼性）
It is considered a universal indicator.
The main objective of the project is to create a universal indicator of market attractiveness for companies and research institutions interested in investment in the emerging markets of mobile telephony.
A universal indicator is typically composed of water, propan-1-ol, phenolphthalein sodium salt, sodium hydroxide, methyl red, bromothymol blue monosodium salt, and thymol blue monosodium salt.
So it is a very complex subject and one particularly difficult to grasp because we still have no universal indicators for putting a monetary value on environmental assets.
