Problem: What is the missing first step of the following process: - Cells in the pancrease release glucagon - The liver in response turns the glucagon into glucose - And releases it into the blood - The blood sugar levels are restored.

A: The blood sugar drops in a body

Problem: What is the missing first step of the following process: - The cracks get very long and big in some places - The earth places pressure against the rocks on both sides of the cracks - The pressure causes the rocks to press against each other very hard - The cracks continue to develop - The earth moves against itself on both sides of the cracks - The pressure and movement around the cracks causes the rocks to crumble in some places - A lot of energy is released - The energy causes seismic waves - The seismic waves move the earth in an earthquake.

A: The earth develops cracks deep beneath the surface

Problem: What is the missing first step of the following process: - A selection of grapes are gathered - The grapes are washed - The stems are removed from the grapes - The grapes are crushed and added to a fermation container - Yeast is added to the container - The yeast eats the sugar in the yeast, releasing alcohol -

A: Grapes are grown

Problem: 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