What were the four locations in which the hijacked planes crashed?

The first two planes hit the twin towers, the third one hit the pentagon, and the fourth one hit a field in Shanksville, Pennsylvania

Explanation:

Two of the planes were flown into the twin towers of the World Trade Center in New York City, a third plane hit the Pentagon just outside Washington, D.C., and the fourth plane crashed in a field in Shanksville, Pennsylvania

Explanation:

3.a

4.d

5.b

6.b

7.c

8.a

9.d

10.a