Answers

2016-06-18T20:18:56+08:00
If there is one cell damaged or treated. Until it begin to ruin from one cell to another.
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2016-06-18T20:21:37+08:00
Diseases form in the Circulatory and Respiratory Systems by:

A harmful bacteria invading the body systems, or
A damaged organ, such as the heart and lungs.

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