All of the factors that can change in an experiment are called variables. Which of the following is true about the variables in an experiment? OA. One variable should be kept the same and at least two variables should change. OB. All variables should change. OC. All variables should be kept the same. OD One variable should change and the others should be kept the same.​

Which of the following is true of photosynthesis? a)carbon dioxide is a reactant b)water is a product c)most reactions within this process are exothermic d)oxygen is a reactant

Are salt and soap nutrients or toxins for yeast? explain.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point