Our Galaxy Is Suspected to Be Surrounded by a Dark

question 41

Multiple Choice

Our galaxy is suspected to be surrounded by a dark halo.What is it about the disk of the galaxy that makes us suspect this?

• A)It rotates faster than expected in its outer region.
• B)It rotates more slowly than expected in its outer region.
• C)It is only visible during a total eclipse of our Sun.
• D)It is surrounded above, below, and well beyond by the brightly glowing corona.

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Definitions:

Fixed Ratio

A schedule of reinforcement wherein a response is rewarded only after a specified number of correct responses, leading to a high rate of responding.

Variable Ratio

A reinforcement schedule where a response is reinforced after an unpredictable number of responses, leading to high and steady response rates.

Fixed Ratio

A schedule of reinforcement where a response is rewarded only after a specified number of responses, in behavioral psychology.

Variable Ratio

A reinforcement schedule that rewards a response after a random number of responses, making it very resistant to being extinguished.