How do historians use primary and secondary sources to study the past?​

Historians use primary sources whenever possible. They use

secondary sources when they want more information about the

past.

Explanation:

These lines describe the loss of the identity of the city though the loss of the empire state buildings.

Explanation:

The world trade center ad the twin towers of the empire state building had been the center and the symbol of US commerce for a long time and were a reminder of its financial power.

They were attacked and torn down and thus the poem concerns with the twin towers.

The poem talks from the perspective of a bird in the sky or perhaps anything in the skyline that misses the grandeur of the two buildings talking about the loss of what was unthinkable to lose.