Problem: What is the missing first step of the following process: - The air enters the mouth and nose - The diaphragm contracts - Air fills all the sacks in the lungs - Oxygen passes through the sacks into capillaries - The blood is passed to the blood in the capillaries - The blood carries the oxygen to the heart - The heart pumps the oxygenated blood to the body.

A: You inhale

Problem: What is the missing first step of the following process: - Add water into the tray - You insert the tray into a freezer - The water molecules begin to slow down - The water becomes ice - The ice cubes are ready.

A: You take a tray

Problem: What is the missing first step of the following process: - The liver uses enzymes to clean the blood - The cleaned blood is expelled - The liver creates bile from the items filtered - The liver takes energy and stores it as glycogen - The bile is sent to the intestines.

A: The liver takes in blood from the rest of the body

Problem: What is the missing first step of the following process: - The coal powder mixes with hot air, which helps the coal burn more efficiently, and the mixture moves to the furnace - The burning coal heats water in a boiler, creating steam - Steam released from the boiler powers an engine called a turbine, transforming heat energy from burning coal into mechanical energy that spins the turbine engine - The spinning turbine is used to power a generator, a machine that turns mechanical energy into electric energy - This happens when magnets inside a copper coil in the generator spin - A condenser cools the steam moving through the turbine - As the steam is condensed, it turns back into water - The water returns to the boiler, and the cycle begins again -

A:
A machine called a pulverizer grinds the coal into a fine powder