Litmus test on an orange. A piece of red litmus paper held against a freshly-cut face of an orange. The lack of change of colour means that the orange must be either acidic or neutral. Oranges,like all citrus fruits,contain citric acid | |
Licence : | Droits gérés |
Crédit: | Science Photo Library |
Taille de l’image : | 4181 px × 4181 px |
Model Release : | Non requis |
Property Release : | Non requis |
Restrictions : | - |