https://www.learnenglish.de/games/adjectives/CompSup.html
https://www.learnenglishfeelgood.com/adverbs-comparative-superlative1.html
http://baladre.info/english/sedaviwebfront/compsup7.htm
http://www.grammarbank.com/adjectives-adverbs-tests.html
https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-29405.php
http://www.web-esl.com/compare/comp.htm
http://www.focus.olsztyn.pl/en-comparative-adjectives-exercise.html#.WhKvS2e3bl8
http://www.esl-lounge.com/student/grammar/3g33-comparative-superlative-prague.php
https://www.englisch-hilfen.de/en/exercises/adjectives_adverbs/adjectives_comparison_sentences2.htm