Sure! Let's revise each question with appropriate verbs or modals:
21. **Could** you speak a little more slowly?
- "Could" is used for polite requests.
22. Johnny! You **shouldn't** play with sharp knives. Put it down immediately!
- "Shouldn't" is used to give advice or warnings.
23. A. Oops! I spilled coffee on my shirt.
B. You **should** run it under hot water.
- "Should" suggests the best course of action in a situation.
24. John is absent today, I think he **might** be sick.
- "Might" is used to indicate possibility.
These choices fit well with the context of the questions.
