Form 6b. Countable and uncountable nouns

For practicing:
https://www.myenglishpages.com/site_php_files/grammar-exercise-countable-uncountable-nouns.php;
https://www.english-4u.de/en/grammar-exercises/a-an-some.htm;
https://www.englisch-hilfen.de/en/exercises/confusing_words/few_little.htm;
https://elt.oup.com/student/solutions/preint/grammar/grammar_03_012e?cc=lt&selLanguage=en.
Homework exercises:
https://www.english-grammar.at/online_exercises/quantifiers/quantifiers1.htm
https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-52605.php.