The document that provides the structure for the us government is

Who is better, messi or cristiano, i need this for a chemistry class. asap

Which real-world scenarios below represent physical and chemical changes? -running a car -exploding fireworks -mixing water and powdered drink mix -combining oil and vinegar to make salad dressing -taking aspirin for a headache -diluting bleach with water-digesting dinner-spreading peanut butter on bread

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon