Sure! Based on the given sentences, here are the closest meanings to each sentence:

1. **"I was reading a newspaper when I saw an advert for a volunteer at the local food bank."**
- **Correct answer:** A. After reading the newspaper, I saw an advert for a volunteer at the local food bank.

2. **"While Ian was watching TV, she saw a lot of people waiting at the food bank."**
- **Correct answer:** D. Ian saw a lot of people waiting at the food bank as soon as she had watched TV.

3. **"It started raining while we were driving up the road."**
- **Correct answer:** C. As soon as it started raining, we drove up the road.

4. **"We were eating dinner when we heard the landslide on TV."**
- **Correct answer:** D. Before we heard about the landslide on TV, we had dinner.

5. **"Ian was walking home when he saw an old lady on the pavement."**
- **Correct answer:** A. After Ian saw an old lady on the pavement, he continued walking home.

6. **"They were cleaning the park when it started to rain."**
- **Correct answer:** A. After they cleaned the park, it started to rain.

7. **"It started to rain while they were cleaning the park."**
- **Correct answer:** B. Before they started cleaning the park, it started to rain.

8. **"I was watching television, I saw the flood warning."**
- **Correct answer:** A. While I was watching television, I saw the flood warning.

9. **"While I was watching television, I saw the flood warning."**
- **Correct answer:** C. I was watching television as soon as I saw the flood warning.

Let me know if you need anything else!