1. The two countries have been ___ war with each other for over a decade.

2. I haven't seen her for ages, but we still keep ___ touch by email.

3. The police believe the fire was started ___ purpose to claim insurance.

4. We need to get the project finished ___ all costs, even if we stay late.

5. I’m afraid this model is ___ of stock at the moment.

6. You can’t smoke here; it’s ___ the law in public places.

7. The situation is now ___ control, so there’s no need for further alarm.

8. You should try to learn these irregular verbs ___ heart.

9. I’m not sure if I can help you, but I’ll do my best ___ any case.

10. Please stay calm and don't get ___ a panic before the exam starts.

11. She’s been ___ a very bad mood since she heard the news.

12. The train arrived exactly ___ schedule, which is quite unusual.

13. I’m writing to you ___ regard to your recent job application.

14. It’s hard to believe that this ancient house is ___ risk of collapsing.

15. We are ___ no obligation to provide a refund without a receipt.

16. I’m not really ___ the mood for going out in this cold weather.

17. Could you please put the documents back ___ place after reading them?

18. I’ve been living in this temporary apartment ___ the time being.

19. The local hospital is ___ threat of closure due to lack of staff.

20. We need to find a solution ___ the problem of plastic pollution.

21. It took him a long time to recover ___ the shock of losing his job.

22. Is there any hope ___ finding the missing hikers before nightfall?

23. They are currently involved ___ a heated debate about climate change.

24. Please refrain ___ talking loudly while the presentation is in progress.

25. There’s a high demand ___ skilled workers in the technology sector.