3. a.) how do you know that vinegar diffused into the cubes?

As an acid, vinegar has a large number of hydrogen ions. When the hydrogen ions come into contact with the pH indicator, the solution changes color.

clinically, some people often have repeated allergies, eczema and respiratory infections or other parts of the infection, in this case, in addition to some routine tests such as tests for white blood cells, immunoglobulin series, lymphocyte subsets, etc., the five immune immunoglobulin tests are also necessary.