A Cross Section of Earth Reveals a Layered Structure That

question 13

Multiple Choice

A cross section of Earth reveals a layered structure that has different thicknesses and densities. How do geologists know this?

• A)From drilling and digging down into the various layers
• B)From observing the characteristics of lava and gas issuing from volcanic vents
• C)From observing the transit times through Earth of waves generated by earthquakes
• D)From comparisons with drill cores taken by robot spacecraft on Mars and Venus

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Definitions:

High-Tech Revolution

The rapid and widespread advancements in technology and digital systems that drastically changed industries, economies, and societies.

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Contestable Market Model

A theory suggesting that a market with free entry and exit can be competitive even if there are few firms, due to potential competition.

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