Here are the corrections for the sentences in the exercise:

1. **The flood victim** are collecting their personal property.
**Correction:** The flood victims are collecting their personal property.

2. **Avoid danger places, such as windows or bookcases, during an earthquake.**
**Correction:** Avoid dangerous places, such as windows or bookcases, during an earthquake.

3. **There is numerous tropical storms in this area every year.**
**Correction:** There are numerous tropical storms in this area every year.

4. **During the storm, we should stays inside the house.**
**Correction:** During the storm, we should stay inside the house.

5. **Oh, the house is shaking! I think we’re having a earthquake.**
**Correction:** Oh, the house is shaking! I think we’re having an earthquake.

6. **More twenty people on these islands are still missing.**
**Correction:** More than twenty people on these islands are still missing.

7. **While she was work on the field, the tornado came.**
**Correction:** While she was working in the field, the tornado came.

8. **It wasn't snowing when I left home that afternoon.**
**Correction:** This sentence is correct as it is.

9. **Volcano destroy hundreds of homes on some small islands.**
**Correction:** Volcanoes destroy hundreds of homes on some small islands.

10. **Whom happened?**
**Correction:** What happened?

Feel free to ask if you need further assistance!