How does comparative advantage benefit developing nations?

Workers are allowed to ask companies for unions and environmental regulations.
Workers come from farms to work in factories, which creates new urban areas.
Foreign companies bring their businesses there, which raises the standard of living.
Foreign companies hire people to work for good pay under clean, safe conditions.

Question

How does comparative advantage benefit developing nations?
 	
	Workers are allowed to ask companies for unions and environmental regulations.
	Workers come from farms to work in factories, which creates new urban areas.
	Foreign companies bring their businesses there, which raises the standard of living.
	Foreign companies hire people to work for good pay under clean, safe conditions.