Answer:
D, The Gadsden Purchase was bought because it was considered a good route for a transcontinental railroad.
Answer:
The Invisible hand makes sure that the prices meet the demands and nothing is crazily priced.
Explanation:
The concept of competition is what causes this, as more producers enter a market the previous producers had to increase the quality of their products or decrease their price in order to make their goods more desirable so as someone finds a better way to produce the good at a better quality the other producers will have to make their good better as well in order to maintain their market share.
The microscope by using tiny glass leanse to see the cells.