Answer:
D. All of these
Explanation:
Mark should control (or keep constant) the location of the plants, the amount of water the plants receive daily, and the amount of fertilizer the plants recieve daily. The only variable that should change is the type of fertilizer that is given to each plant.
During a scientific experiment, only variable should be changed by the investigator. All other variables should be kept constant.
Answer: if Cedric doesn`t like the class because he is bored or doesn`t understand he could go ask Mr. jacobs for extra help on assignments. He could ask if there are any youth groups that teens like himself are in and he could go make friends there. He could also ask his dad if he can visit his old friends in Chicago for the weekend and maybe that would make him feel better.
