Why have these postulates not been used for HIV?

Most animal cell membranes have proteins that pump. ions out of the cell and potassium ions into this

When ash and dust begin to settle on the ground, they eventually become compacted by

Aresearcher created three groups based on participants bmi: normal weight, overweight and obese. the hypothesis being tested is that the three groups differ in the mean number of artificially sweetened drinks consumed weekly. which statistical test might the researcher use, assuming a reasonably normal distribution of values.