Suppose the demand for books goes down when the price of video games goes down. We can say that these two goods are A. perfect substitutes. B. substitutes. C. unrelated goods. D. complements.

The type of cloud shown here may produce heavy rainfall. this type of cloud most likely occurs in an area of the sub-saharan that is a) often dry. b) often wet. eliminate c) very windy. d) usually cool.

Which of the following was not a result of early humans increasing proficiency at finding food

Where do most people in arabia and iraq live? a. in the fertile crescent b. in the rub, al-khali c. in cities d. in and around mecca