What is the missing first step of the following process: - People burn coal for heat or electricity - Pollution from the coal goes into the sky - Coal pollution enters clouds - Clouds rain over an area - The polluted rain becomes acid rain.
Ans: People dig up coal from the ground

What is the missing first step of the following process: - Pick a spot to plant them - Dig a hole in the dirt - Put the seed in the hole - Pour some water on the seed and hole - Cover up the hole - Press down on it - Spray some plant food on it.
Ans: Get some seeds

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.
Ans: Air travels into the body

What is the missing first step of the following process: - The particles remove small pieces of the rock each time they touch the rocks - The particles continue to hit, brush against, or grow against the rocks - The rock eventually is broken apart by this contact - The pieces of the rock are now small rocks - The rock pieces are worn away into smaller and smaller pieces by the same forces -
Ans: Particles in the environment interact with rocks