Sure! Here are the filled-in blanks for each sentence:

1. I last saw Bob when I was in Ho Chi Minh.
I haven't **seen Bob since I was in Ho Chi Minh.**

2. I'm only interested in why he did it.
The only thing **I care about is why he did it.**

3. Please don't give me an injection.
I would rather **not have an injection.**

4. Everyone heard about the news before I did.
I was the **last to hear about the news.**

5. You don't need to finish the work today.
It's not **urgent to finish the work today.**

6. "I'm sorry that I broke your ruler, Tom," said Dick.
Dick apologized **for breaking Tom's ruler.**

7. You really should be able to dress yourself by now!
It's high **time you could dress yourself!**

Let me know if you need any more help!