What are some examples of job specialization

What was eleanor roosevelt's most significant achievement?

7. how did the early egyptians use the flooding of the nile river to their advantage? they diverted the water to flood their enemy's lands and destroy their crops. they created an easier way to travel to the mediterranean sea and the indian ocean. they established a new water-based athletic event for the ancient olympics in greece. they devised an innovative irrigation system, which created a surplus of food.

Which of the following was probably the most difficult challenge facing construction of the railroad?