According to the U

question 28

Multiple Choice

According to the U.S. Census Bureau, in the last 50 years, the birth rate has __________.

• A) been up and down
• B) steadily declined
• C) stayed consistent
• D) risen significantly

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Definitions:

Depletion Time

The estimated time it will take to use up a resource at its current rate of consumption.

Mineral Reserves

Quantities of minerals that can be profitably extracted and processed with current technology.

Metallic Mineral

Minerals from which metal can be extracted, typically characterized by a shiny, metallic luster and conductivity of heat and electricity.

Zinc

A metallic element required in small amounts by most living organisms for enzyme function, DNA synthesis, and immune response.