Rephrasing keys

1. We´d better leave them a note, because it´s possible they´ll arrive later
(case)We´d better leave them a note in case they arrive late.
2. He speaks German extremely well
(command) He has a good command of German
3. His criticisms are quite unfair
(justification) His criticisms have no justification
4. I can´t understand why they are reluctant to sign the contract
(baffled) I am baffled by their reluctance to sign the contract
5. I always find chess problems like that quite impossible
(defeat) Chess problems like that always defeat me
6. This must be kept secret
(know) Nobody should know this secret
7. I can´t afford a new dress; that old blue one will have to do
(make) I can´t afford a new dress; that old blue one will have to make do
8. You may choose to take early retirement
(option) You have the option to take early retirement
9. I only called the police when I had tried everything else
(resort) My last resort was to call the police