Problem: What is the missing first step of the following process: - Waste enters the kidneys - A processing moment in the kidneys let waste and fluid pass - Prevents larger molecules to pass - Fluid goes back to the bloodstream - Bad waste is removed - The final product is turned into urine.

A: Fluid

Problem: What is the missing first step of the following process: - Through warming or other methods a chunk is taken off the glacier - The chunk drifts into the sea - And it settles where it can remain in its state - It is considered an iceberg.

A: You start with a glacier

Problem: What is the missing first step of the following process: - Water is in the air - The water forms tiny ice crystals - The ice crystals collide with each other - The ice crystals stick to each other - The ice crystals get bigger as more of them stick together - The ice crystals get too heavy to be in the air - The ice crystals become snowflakes - The snow flakes fall to the ground as snow.

A: The air is cold

Problem: What is the missing first step of the following process: - Ice inside the cloud bumps around and causes electrostatic charges - The cloud becomes a thundercloud - Electrostatic energy builds and forms a strong negative charge - Positive energy is attracted to the negative energy in the cloud - This positive energy gathers on the ground - The positive energy connects with the negative energy and forms lightning.

A:
Ice forms inside a cloud