Problem: What is the missing first step of the following process: - The bird is nurtured by its parents - And is fed food for growth - The bird grows - Begins to learn how to fly - The bird matures - The bird leaves its nest - The bird makes its own nest.

A: A bird hatches from an egg

Problem: What is the missing first step of the following process: - Winter comes and the animal finds a place to hibernate - Over a period of days, the animal's heart rate and breathing rate drop slowly - Electrical activity in the brain almost ceases completely, though some areas remain active - The animal has entered hibernation mode -

A: The animal eats large quantities of food that will be stored as fat

Problem: What is the missing first step of the following process: - The water tank over the boiler is heated - Creates steam - The steam is funneled to the piston - Piston uses the steam as energy - The piston causes the crankshaft to move.

A: Coal is heated in the boiler

Problem: What is the missing first step of the following process: - Two types of proteins exist in filaments in the muscles - The filaments move when the brain instructs them to - The motion of the filaments cause the muscle to shorten and contract - Opposing pairs of muscles exist in order to provide the necessary range of motion.

A:
Electrical signals in the brain travel through nerves to muscles