Daily iron supplementation is recommended as a public health intervention in school-age children aged 60 months (i.e. 5 years old) and older, living in settings where the prevalence of anaemia in infants and young children is 40% or higher, for preventing iron deficiency and anaemia
She should start washing her hands, going to the doctor so she can figure out what type of medicine to take so she avoids sickness
In a study, the independent variable is the thing that you change to see how the change produces different results. In this study, the independent variable would be the use of nicotine.