What have scientists inferred about the outer portion of the earth's core by monitoring the time of arrival of p- and s-waves at monitoring stations around the world? a. it is a dense solid. b. it is liquid-like. c. it is organic material. d. it is a pressurized gas.

Which of the following is true about fossils? a. the relative age of fossils cannot be determined from their position in sedimentary layers. b. fossils found in lower layers of sedimentary rock are as old as fossils found in upper layers of sedimentary rock. c. fossils found in upper layers of sedimentary rock are older than fossils found in lower layers of sedimentary rock. d. fossils found in lower layers of sedimentary rock are older than fossils found in upper layers of sedimentary rock.

Examine the population chart of niger. based on this chart, niger is in the stage of thompson’s demographic transition. a. balance b. growth c. leveling d. replacement

What was the first official pair of sister cities?