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It is difficult to obtain enough calcium without consuming milk or other dairy foods.

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When blood is deoxygenated and flowing back to the heart through the veins, it is dark reddish-blue in color. Blood in the arteries that is oxygenated and flowing out to the body is bright red. Whereas arterial blood comes out in spurts, venous blood flows.

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Essential fatty acids have been shown to be effective against ulcers, asthma, dental cavities, and skin disorders such as acne.

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Patients who cannot swallow may receive nutrition via a parenteral route—usually, a catheter is inserted through the chest into a large vein going into the heart.

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Hyperthyroidism leads to an increased rate of metabolism and affects about 1% of women but only 0.1% of men. For most people, this increased metabolic rate causes the thyroid gland to become enlarged (known as a goiter).

Foliage height diversity and bird species diversity (data from MacArthur and MacArthur 1961). Foliage height diversity and bird species diversity (data from MacArthur and MacArthur 1961).
Four kinds of evidence supporting the theory that species evolve. Four kinds of evidence supporting the theory that species evolve.
Earth’s orientation Earth’s orientation
Earth-Moon-Sun Positions during the Neap Tide Earth-Moon-Sun Positions during the Neap Tide
Rita borrows $4,500 from the bank at 9 percent annually compounded interest to be repaid in ... Rita borrows $4,500 from the bank at 9 percent annually compounded interest to be repaid in ...
Earth’s tilt and yearly rotation around the sun cause seasonal effects. The 23° tilt of Earth’s ... Earth’s tilt and yearly rotation around the sun cause seasonal effects. The 23° tilt of Earth’s ...
Video: Types of disease resistance: innate defenses & immunity

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