1https://agendaweb.org/exercises/grammar/countable-uncountable/how-much-how-many-test-1
2https://agendaweb.org/exercises/grammar/countable-uncountable/how-much-how-many-test-2
3https://agendaweb.org/exercises/grammar/countable-uncountable/how-many-much
4https://www.englisch-hilfen.de/en/exercises/confusing_words/much_many4.htm
5https://www.englisch-hilfen.de/en/exercises/confusing_words/much_many3.htm
6https://www.english-room.com/howmuch.htm
7https://www.tolearnenglish.com/exercises/exercise-english-1/exercise-english-856.php
9https://www.english-4u.de/en/grammar-exercises/how-much-many.htm