How many groups did aristotle use to divide all of the organisms in the world?

Which summarizes the relationship between density of an element and its distribution in earth? a. the greater an element’s density, the greater the amount of it found in the crust. b. the denser an elements is, the smaller the amount of it earth core. c. the greater an elements density, the smaller the amount of it’s found in the crust

Which of the following is not a challenge to instituting sound global environmental policies? a. most changes are inexpensive and easy to implement. b. elected leaders who support unpopular environmental issues often are not re-elected. c. economic considerations outweigh environmental ones in many societies. d. there is no way to enforce international environmental agreements.

Given: circle a externally tangent to circle b. how many possible common tangents to circles a and b can exist? 2 3 4