Question

.

Answer 1

a

Answer 2

Esconderse, is your answer.

Answer 3

Ser, is your answer.
It can be esconderse, or esconder.

Answer 4

All meant hide, but one. So, go Elisa. Lol. :3

Answer 5

I'm Panamanian, Puerto Rican blood, some Spanish areas have their own dialect. (:
Confirmation on ser, is correct.