Respuesta:
1. My son was playing tennis last summer.
2. Michael was climbing the mountain for three days.
3. It was snowing a lot at the top of the mountain.
4. Juan was sleeping a lot last week.
5. My mother was preparing dinner last weekend.
6. Sarah was sending applications to that company last month.
7. The tourists were visiting various places in the city.
8. Sally was singing a beautiful song during the concert last night.
9. Tom was working very hard last month.
10. Sam was having fruit for breakfast all month
