Here are the completed sentences:

1. I’ve known Jack **for** 10 years.
2. We will leave as soon as she **is** ready.
3. My sister is very **good** at cooking. She can make delicious meals.
4. **Would** you like to join us for dinner tonight?
5. I’m so tired. I think I’ll go to bed **early**.
6. The weather has been very hot **since** last week.
7. You should **read** the instructions carefully before you start the project.
8. He is the **kindest** person I know. He is always helping others.
9. The cake smells **delicious**. I can’t wait to eat it!
10. I was so surprised when I **found out** that they had already left.