What is required before using a respirator?

Which nutrient is the most difficult to break down and, thus, is generally used last fro energy in the body? water carbohydrates fats proteins

Smoking cigarettes is a pervasive habit found in many parts of the world and a habit that could be explained by both microsociological and macrosociological forces. give an example of each that would be relevant to explaining the proliferation of smoking. how might your suggested micro- and macro-level analyses be linked

Which of the following is an argument against buying local fruits and vegetables?