1. Why is Earth's temperature just right for life?
A: Earth's core is hot enough to heat Earth's surface.
B: Earth's magnetic field creates suitable temperatures on Earth's surface.
C: Earth's crust is warmed by heat from the sun
D: Earth's atmosphere traps heat from the sun, which makes Earth's temperature suitable for living things
2. Which of the following statrements accurately explains how Earth's atmosphere supports life
A: Earth's atmosphere contains 78 percent oxygen, which is essential for life.
B: Earth's atmosphere contains 21 percent oxygen, which many life forms need to survive
C: Earth's atmosphere contains more oxygen then carbon dioxide
D: Earth's atmosphere contains carbon dioxide, which all life forms breathe in