Can you give the correct forms for the verbs in square brackets?

1. They fell asleep soon after they had [lie] down.
2. Once again the dog had [lay] its head on her lap.
3. He remembered he had [drink] the cocktail before.
4. I got up immediately after I had [wake] up.
5. Their efforts failed, though everyone had [strive] for success.

For the answers read This is highly irregular in the Macmillan Dictionary Blog.