Choose the correct article for each sentence:
1. That is a /an/ the third bird I have seen today.
2. I have a /an/ the English class after lunch.
3. That was a /an/ the extraordinary performance.
4. There is a /an/ the pile of books on my desk.
5. I am expecting a /an/ the visitor very soon.
6. A/An/The apricot would be good with this ice cream.
7. I sent you a /an/ the postcard from Italy.
8. I think I accidentally threw a /an/ the envelope away