The correct verbs for #1 are in the order:
Monte
Tomamos
Mandaron
Acampastes
The correct verbs for #2 are in the order:
Visitaron
Tomaron
Compraron
Regateaban
Mandaron
The answers for #3 are in the order:
Tomamos muchas fotos de nuestras vacaciones.
Nadie nos mando tarjetas postales.
Compramos unas camisetas bonitas por un bien precio
The closest adjective (opposite) of the word Gorda is Delgado
Answer: C, Delgado
Venga a nuestra casa is used for someone who should respect or who is elderly so this would be the right choice.
Ven a nuestra casa would be used to refer to maybe your close friends or people you can be casual with :)