What inventions brought about a growth in global trade in the 19th century?

What river valley civilization in the plow

How did the growth of railroads american businesses expand

In a study, people were asked to imagine simple occasions that made them happy and to remember events that made them feel proud about themselves. it was observed that the subjects developed an increasingly positive attitude. these changes are known to be healthy, leading to greater physical activity and reducing unhealthy habits. based on this excerpt, we can conclude that a positive attitude .