1. was watching
2. died
3. rang
4. was cooking
5. was having
6. came
7. was going
8. came
9. were studying
10. happened
11. was walking
12. was sleeping
13. met
14. was skiing
15. was shopping
16. started to rain (?)
17. saw
18. were fighting
2)
1. heard, were speaking
2. told, were playing
3. was listening, dropped
4. was making, rang
5. were walking, started
6. was riding, hit
7. were sleeping, began
8. was having, came
9. was planting, was jumping
10. were having, went
11. was eating, landed
12. were playing, came
13. left, arrived
14. was reading, heard
15. was having, visited
16. was crossing, saw
17. was choosing, came
1. was watching
2. died
3. rang
4. was cooking
5. was having
6. came
7. was going
8. came
9. were studying
10. happened
11. was walking
12. was sleeping
13. met
14. was skiing
15. was shopping
16. started to rain (?)
17. saw
18. were fighting
2)
1. heard, were speaking
2. told, were playing
3. was listening, dropped
4. was making, rang
5. were walking, started
6. was riding, hit
7. were sleeping, began
8. was having, came
9. was planting, was jumping
10. were having, went
11. was eating, landed
12. were playing, came
13. left, arrived
14. was reading, heard
15. was having, visited
16. was crossing, saw
17. was choosing, came
Потому что это вопрос к предложению It snows a lot in Iceland. Время present simple. Snow является глаголом.