Here are the completed sentences with suitable connectors:

1. She went on walking **although** she was terribly tired.
2. It is raining; **nevertheless**, we went out.
3. The food of this restaurant isn’t delicious. I like the decoration, **though**.
4. **In spite of** his sickness, he still had to go to school.
5. I knew what he wanted **despite** not understanding the words.
6. **Although** he behaves impolitely, everybody still loves him.
7. **Despite** the traffic jam, we went home early.
8. **Although** I studied very hard, I failed the placement test.
9. She could not forget him, **however** hard she tried.
10. I knew everything. I, **however**, tried to pretend I didn’t know.
11. She was really bad at cooking. Everyone is still satisfied with the meal, **nevertheless**.
12. I feel a little scared; **however**, I will talk to him.
13. Mike drove carefully; **nevertheless**, Mike couldn’t avoid the accident.
14. Lisa finished the cake **although** she said she didn’t like sweets.
15. The sky was gray and cloudy, **so** we went to the beach.