Singular count nouns that haven't been specified or are unknown to the audience take
the indefinite article.
Mark the sentences that follow this rule. Only
mark the correct sentences:
1)
I bought a car last night. The car I bought is
really nice.
2)
She found a quarter in the street. The
quarter was covered in mud.
3) They had a dog, a dog ran away.
We lost a book in the elevator. A book was
4)
green.
5)
I need to buy a pen. A pen I need cost too
much money.