A Quasar Is Now Thought to Be

question 21

Multiple Choice

A quasar is now thought to be

• A) the central core of an active galaxy.
• B) a very active,very distant star.
• C) a long-lived supernova explosion.
• D) a nearby star,ejected with great violence out of a galaxy.

---

Definitions:

Coins

Pieces of metal issued by the government as money, typically used as lower-value currency.

Barter

An exchange system where goods or services are directly exchanged for other goods or services without using a medium of exchange, such as money.

Commodity Money

A type of money whose value comes from a commodity of which it is made, such as gold or silver.

Goldsmiths

Historical tradespeople who crafted objects out of gold and were also involved in banking activities, such as issuing loans and safekeeping valuables.