Q: Keywords: horse, saddle, wait
What is a sentence that includes all these keywords?

A: saddle waiting for a horse

Q: Keywords: fountain, run, soak
What is a sentence that includes all these keywords?

A: A little boy in his clothes running through a fountain and getting soaked.

Q: Keywords: cat, relax, top
What is a sentence that includes all these keywords?

A:
A cat relaxes on top of a bag.