It Took More Than 100 Years for the World's Population

question 8

Multiple Choice

It took more than 100 years for the world's population to double from 1 billion to 2 billion. How long did it take for the world's population to increase from 4 billion to 5 billion?

• A) Fewer than 15 years as the result of exponential growth
• B) Half the time of the first doubling, about 50 years
• C) More than 100 years; 1 billion people are added each 100 years
• D) The world's population has not yet reached 5 billion

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Definitions:

Wrist Actigraphy

A monitoring method using a wrist-worn device to record motion, often used to study sleep patterns.

Muscle Tone

The continuous and passive partial contraction of the muscles, or the muscle's resistance to passive stretch during resting state.

Ritualizing Cues

Specific signals or actions that prompt ritualistic behaviors or routines, often observed in psychological contexts or religious practices.

Well-lit

An area or space illuminated brightly and clearly, making it easy to see.