How to make these sentences into Plural? (a pupil is not a teacher...)

English as a Second Language English Vocabulary, Grammar and Idioms
1
  1. a pupil is not a teacher
  2. a hen is a bird
  3. he is a doctor
  4. she is pretty girl
  5. here is a pen and a pencil
  6. a camel is a big animal
  7. an egg is white
  8. there is a car behind you
  9. a donkey is bigger than a cat
  10. a lazy boy is not a good pupil
2
  1. Pupils are not teachers.
  2. Hens are birds.
  3. The men are doctors.
  4. They are pretty girls.
  5. Hare are some pens and pencils.
  6. Camels are big animals.
  7. Eggs are white.
  8. There are cars behind you.
  9. Donkeys are bigger than cats.
    10.Lazy boys are not good pupils.
3
  1. They are doctors.
  2. Here are (some) pens and pencils.
  3. There are (some) cars behind us.