Explain why the BREATHING RATE of students increased after exercise. Include information about what happens at the level of body systems and at the cell. Explain why the HEART RATE of the students increased after exercise. Include information about what happens at the level of body systems and at the cell.

When exercising, your body uses more oxygen and produces more carbon dioxide and your muscles also need energy to contract because of this your breathing needs to increase.

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all these collisions do one thing, and that thing is explained in the last option. when dusst, rocks and ice collide, they harden and form giant layers of rocks or hard ice.

d)   to harden materials to form different parts of earth’s layers

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bioteacher101

answer; /// the shaft of the hair consists of dead cells;