Sure, here are the completed sentences:

1. I don’t know why Fred made such an extraordinary decision. (prompted)
=> I don’t know **what prompted Fred to make** such an extraordinary decision.

2. Inefficient treatment of customers creates a bad impression of the company. (reflects)
=> Treating customers with a lack **of efficiency reflects badly on** the company.

3. The organizers planned everything as carefully as they could possibly have done. (utmost)
=> Everything was planned **with the utmost care** by the organizers.

4. Coming second didn’t make her feel any better because she only wanted to win. (consolation)
=> Coming second **was no consolation to her because winning** was all that mattered to her.

5. I promised him that the situation would not be repeated in the future. (word)
=> I **gave him my word that there would be** no repetition of the situation in the future.

6. The inhabitants were far worse-off twenty years ago than they are now.
=> The inhabitants are nowhere **near as badly off as they were** twenty years ago.

7. The chairman’s leaving just before you’re due to arrive.
=> By the **time you arrive, the chairman will have left.**

8. It was difficult to understand her colleagues’ open hostility towards her proposal.
=> That her colleagues **were openly hostile towards her proposal was difficult to understand.**

9. They only reimbursed us because we took legal advice.
=> We wouldn’t **have been reimbursed if we hadn’t taken legal advice.**

10. We’ve had lots of arguments with that particular harbor master before.
=> This isn’t **the first time we’ve had arguments with that particular harbor master.**