Complete the sentences using contracted forms (e.g. He's not He has).
1. He...... (be) crazy about jazz ever since he was five years old.
2. They....... (finish) making the film in about six months' time.
3. By the time Lord of the Rings came out on DVD, i...... (see) it three times.
4. I think i..... (go) to that exhibition, but I can't remember when.