The key answer of exercise 1

a)

A man who had been presumed drowned at sea turned up at a police station claiming he couldn't remember anything.

c)

1. He was tanned because he had been living in Panama.
2. He'd pushed his canoe out to sea.
3. He'd been hiding in his house for most of the time, but later travelled to Greece and Panama.
4. His deception was uncovered and he and his wife were sent to prison. They were later released and got divorced.