Which Statement Is True of the Modern World's Population

question 13

Multiple Choice

Which statement is true of the modern world's population?

• A)seems to be stabilizing at about 6 ½ billion people
• B)is increasing exponentially and may have dire results
• C)may decline by mid-century if AIDS and other communicable diseases are not controlled
• D)is concentrated mostly in Africa
• E)is predicted to be rebalanced sometime during the 21st  century by a global catastrophe

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Definitions:

Diastole

The phase of the heart cycle when the heart muscle relaxes and allows the chambers to fill with blood.

Ventricular Filling

The phase of the cardiac cycle in which the ventricles fill with blood, following diastole and before systole.

AV Valves

The atrioventricular valves, which include the mitral and tricuspid valves, control blood flow between the atria and ventricles in the heart.

Semilunar Valves

Heart valves located at the bases of the aorta and the pulmonary artery that prevent blood from flowing back into the ventricles.