Sure, here are the sentences completed:

1. **The child will die if nobody sends for a doctor.**
**Someone must send for a doctor, or the child will die.**

2. **He always has his nose in a book and never pays attention to what I say.**
**If he didn't always have his nose in a book, he might pay attention to what I say.**

3. **Alice and Charles did not decide to move to a bigger house until after the birth of their second child.**
**Only when their second child was born did Alice and Charles decide to move to a bigger house.**

4. **You are under no obligation to accept their offer.**
**You can please yourself whether you accept their offer or not.**

5. **The Pacific Ocean is on average deeper than the Atlantic.**
**The average depth of the Pacific Ocean is greater than that of the Atlantic.**

6. **He’s having a lot of trouble now because he lost his passport last week.**
**If he hadn't lost his passport last week, he wouldn't be having a lot of trouble now.**

7. **When the police caught him, he was trying to climb over the garden wall.**
**The police caught him trying to climb over the garden wall.**

8. **His ability to run a company really impresses me. (IMPRESSED)**
**I am really impressed by his ability to run a company.**

9. **If Peter hadn’t been interested, the project would have been abandoned.**
**But for Peter's interest, the project would have been abandoned.**

10. **People think the jewels were stolen by one of the guests.**
**One of the guests is thought to have stolen the jewels.**

11. **Nobody had invited Jane to the party, which annoyed her.**
**As Jane had not been invited to the party, she was annoyed.**

12. **It is pointless to have that old washing machine repaired. (WORTH)**
**It is not worth having that old washing machine repaired.**

13. **Tony only understood very little of what the teacher said. (HARDLY)**
**Tony hardly understood anything of what the teacher said.**

14. **Mrs. Scott is proud of her cooking. (TAKE)**
**Mrs. Scott takes pride in her cooking.**

15. **When I left she said that she hoped I had a pleasant journey. (WISHED)**
**When I left, she wished me a pleasant journey.**

16. **I’ve lost interest in going to the same place all the time. (FED)**
**I am fed up with going to the same place all the time.**

17. **His smooth manner didn’t deceive us. (TAKEN)**
**We were not taken in by his smooth manner.**

18. **The police think the man holding the hostages is heavily armed.**
**The man holding the hostages is thought to be heavily armed.**