Q: What is the missing first step of the following process: - Air reaches the lungs - The lungs absorb the oxygen from the air - The oxygen is transported by hemoglobin - Red blood cells are made of hemoglobin - Blood has a lot of red blood cells - The heart moves the blood throughout the body - Blood can bring the oxygen to different cells in the body.
A: Air travels into the body

Q: What is the missing first step of the following process: - The water freezes into ice - The cracks expand - Over time the rocks split - The rocks are now in smaller pieces.
A: Water gets into cracks in rocks

Q: What is the missing first step of the following process: - The basidia gives off spores - The spores germinate - The spores create Hyphae - Multiple Hyphae meet and converge - They join with Mycelium - A hyphal knot forms in the ground - A primordia shoots out of the ground - A mushroom cap is formed.
A: A mushroom gives off gills lined with basidia

Q: What is the missing first step of the following process: - Chemical compounds rise into the air - Chemical compounds mix with elements in clouds - The affected rain falls to the earth - The affected rain can harm natural and man-made objects because of its acidic content.
A:
Human industry produces chemical compounds