Are these sentences are all OK?
1-1. The book is too interesting to put it down.
1-2. The book is so interesting that you won't/can't put it down.
2-1. The book was too interesting to put it down.
2-2. The book was so interesting that I couldn't put it down.
3-1. I am too busy to have enough time to sleep.
3-2. I am so busy that I don't have enough time to sleep.
Thank you very much.