What Causes a Planetary Nebula

question 4

Multiple Choice

What causes a planetary nebula?

• A) shocks from colliding winds around dying stars
• B) planetary collisions
• C) supernovae
• D) fragmentation of giant molecular clouds

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Definitions:

September Futures Contract

A futures contract with an expiration date in September where assets can be commodities or financial instruments, stipulating sale or purchase terms for future delivery.

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A precious metal with high thermal and electrical conductivity, used in jewelry, currency, and as an investment commodity.

Troy Oz

A unit of measure for the weight of precious metals, traditionally equal to about 31.1035 grams.

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