Here are the correct answers for each blank:

1. **C. organised** - "The first Glastonbury Festival took place in 1970 and was organised by Michael Eavis..."
2. **B. in** - "...who still runs the festival now in his farm in Somerset..."
3. **A. so** - "...Only 1,500 people attended on that occasion, so this number has grown exponentially since then."
4. **C. more** - "...In 2011, there were approximately 100 times more people in the crowd..."
5. **B. sold** - "...and tickets, which cost £195 each, sold out within 4 hours."
6. **A. performing** - "...Although it is best known for contemporary music, Glastonbury is host to other performing arts such as dance, comedy and theatre."

So the complete passage with the correct answers would look like this:

The first Glastonbury Festival took place in 1970 and was **organised** by Michael Eavis, who still runs the festival now **in** his farm in Somerset in the south-west of England. Michael charged people just £1 to enter, and the ticket included free milk from the farm. Only 1,500 people attended on that occasion, **so** this number has grown exponentially since then. In 2011, there were approximately 100 times **more** people in the crowd and tickets, which cost £195 each, **sold** out within 4 hours. The festival takes place almost every year in the last weekend of June and lasts for three days. Although it is best known for contemporary music, Glastonbury is host to other **performing** arts such as dance, comedy and theatre.