What’re these other two countries for standard of livingjsjdjdn

Which of there factors contributed most to us westward expansion in the second half of the nineteenth century?

As heat and pressure increase, ductile deformation becomes less likely becomes more likely is replaced by elastic deformation stops occurring

How have ethnic groups shaped the population in central america and the caribbean? how has migration shaped the population in central america and the caribbean? how has small land areas shaped population in central america and the caribbean? how has a rapid population growth shaped the population in central america and the caribbean?