The Last of Us Part I

As I played through the entire game, I was scratching my head about what I missed. The option fell on smoke bombs. To make them easily, load the battle Pittsburgh - bookstore and on the right side go up to the second floor, there will be a door that, according to the plot, needs to be opened by sharpening, in battle the door will be open, fly in, collect loot, and craft a smoke grenade or whatever you want necessary