1. 2. Have (just) arrived
4. Have helped
5. Hasn't occured
6. Has collapsed
7. Has (never) been
8. Have come
9. Hasn't been
10. Has survived
2. 1. Where have you worked as a volunteer?
2. How has the tornado stopped?
3. Why nave we moved to the country since spring?
4. What has destroyed the town?
5. Where have the villagers Come from?
6. What have volunteers cleared?
3. 1. Never
2. Already
3. Yet
4. Just
5. Already
6. For
7. Yet
8. Never
9. Since
10. Never