Name a easy planet to do a assignment on not mars

When should a bar graph be used? a. when there is no independent variable. b. when the independent variable is continuous and does not show a relationship to the dependent variable. c. when the independent variable is continuous and shows a causal link to the dependent variable. d. when the independent variable is composed of categories and does not show a relationship.

Which of the following systems in absorbing oxygen and releases carbon dioxide

Need with these questions . need the answers in a rush for these questions are the answers i put down are correct or not? ?