Astronauts floating around inside the space shuttle are not actually in a zero-gravity environment. explain what is the real reason astronauts seem weightless.

the first phase of the government’s plan for settlement was building the transcontinental railroad. the railroad provided a way to bring settlers and manufactured goods west and ship their agricultural and mining produce east. the transcontinental railroad was an essential artery for rapid development of the frontier.

the second phase of the government’s plan was a liberal land distribution policy that made it possible for many people to homestead. with these two key elements—transportation and cheap land—the government rapidly achieved its goal of persuading people to move west, settle on farms, and push back the frontier.

heat from the core of the earth causes convection currents to occur in the mantle. these currents slowly move the crust around.