PAST SIMPLE VS PAST PERFECT SIMPLE

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex02

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex03

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex04

https://www.ego4u.com/en/read-on/countries/usa/tour/orlando

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex06

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex07

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/exercises?ex08

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/tests?test1

https://www.ego4u.com/en/cram-up/grammar/simpas-pasper/tests?test2

http://www.englisch-hilfen.de/en/exercises/tenses/past_perfect_simple_past.htm

http://www.english-4u.de/past_perfect_ex5.htm

http://www.englishtenses.com/test/past_perfect_or_past_simple

http://first-english.org/english_learning/english_tenses/comparison_tenses/40_simple_past_or_past_perfect_exercises.htm

http://www.englishpage.com/verbpage/verbs11.htm

https://english.lingolia.com/en/grammar/tenses-comparison/simple-past-past-perfect/exercises