Problem: What is the missing first step of the following process: - The oxygen travels to the lungs through the windpipe - The air sacs in the lungs send the oxygen into the blood stream - The carbon dioxide in the blood stream is transferred to the air sacs - The lungs expel through the nose or mouth back into the environment.

A: You breathe oxygen into your body through the nose or mouth

Problem: What is the missing first step of the following process: - The pressure causes plates to move - Magma explodes to the surface - The lava from the eruption cools to form new crust - After several eruptions, the rock builds up and a volcano forms -

A: Magma rises through cracks in the Earth's crust

Problem: What is the missing first step of the following process: - Centrioles separate to move to opposite poles - Metaphase, the chromosomes line up in the center - Anaphase, the chromatids separate - Are pulled apart - Telophase, the chromosomes gather at opposite poles - Two new nuclear membranes form - The cell membranes pinch - Divide into two individual cells -

A: Prophase, the chromosomes become visible

Problem: What is the missing first step of the following process: - The air travels into the windpipe - The windpipe divides the air to the two lungs via the bronchial tubes - The lungs oxygenate the blood in the body - Carbon dioxide is filtered out by every cell in the body - The carbon dioxide is carried back to the lungs via the bloodstream - The carbon dioxide is exhaled.

A:
Air is taken into the body via the nose or mouth