I don’t understand the question..
I don't think the sentence would make any sense if you would have even tried to put any "tu" in the it.
The correct word to fill the blank and complete the sentence is, leyendo.
¿Qué estás haciendo? Estoy leyendo un libro muy interesante.
Perezosos.
Egoistas means rude/selfish, jovenes means young, suaves means soft, which make no sense.
