100 points
the most difficult part of laying the tracks for the transcontinental rail line probably was

a. crossing the rocky mountains and sierra nevada

b. crossing the great plains.

c. crossing the appalachian mountains.

d. crossing the ohio and mississippi rivers.

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.

Analyze the map below and answer the question that follows. image by mdf the map projection above was created using mathematical formulas to calculate distances. it has a small amount of distortion. which map projection is shown in this image? a. the goode projection b. the political projection c. the mercator projection d. the winkel tripel projectio

Which of the following is the main purpose of using an anchored network of booms which funnel debris to a collection area?