1. https://www.english-4u.de/en/grammar/past-simple.htm
2. https://www.english-4u.de/en/tenses-exercises/past-simple.htm
3. https://www.english-4u.de/en/tenses-exercises/past-simple2.htm
4. https://www.english-4u.de/en/tenses-exercises/past-simple4.htm
5. https://www.english-4u.de/en/tenses-exercises/past-tense.htm
6. https://www.english-4u.de/en/tenses-exercises/simple-past.htm