Resposta :
1.
a) It's
b) She's
c) He's
d) He's
e) She's
f) It's
2.
a) Are
b) Is
c) Are
d) Is
e) Is
f) Are
g) Am
h) Is
i) Is
j) Is
k) Are
l) Are
3.
They aren't friends.
Sam isn't at home.
Liz and Kate aren't at school.
Tim isn't eleven years old.
Dan isn't a student.
You are not happy.
I am not in the park.
She isn't s doctor.
He is not a pilot.
It isn't a cat.
We are not students.
My dogs aren't funny.