1-b
2-a
3-c
I speak Spanish so my answers are for sure correct
Soy (yo form, present tense) - use when describing traits about yourself (permanent traits, not thoughts/feelings/locations/etc)
Era (yo/el/ella/usted form, past tense) - directly translates to 'was.' use when describing something in the past
C. viviste. Mi hermananen Los Estados Unidos Durante did a? os