Which of the following theories describes how solar systems form?

Magma forms at divergent boundaries due to _____________.

Oceanic lithosphere tends to be thicker than continental lithosphere.

Which of the following is the least dense?

The Universe has cooled as it has expanded.

Elements heavier than iron were created during the Big Bang.

eBay creates value by:

Use the following to answer questions 21-22.  Figure: Gains from Trade (Figure: Gains from Trade) Refer to the figure. What are the unexploited gains from trade at the free market equilibrium?

The basic postulate of economics indicates that changes in incentives influence the:

Which is a positive economic statement?