The root word which means "red" is a. erythr/o.
Just think about biology - you should know that red blood cells are called erythrocytes, where you can obviously see that root word.
Leuk/o refers to white color, and the other two options do not refer to colors at all.
A risk factor<span> is any attribute a characteristic or exposure of an individual that increases the chance of developing a disease or injury
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Answer: Between the first and second heart sounds of the cardiac cycle, systole is a time of contraction of the heart's ventricles (the sequence of events in a single heart beat).
Explanation:
