Angličtina pro matematiky II
Týden 8
https://www.grammarly.com/blog/articles/ or
https://owl.purdue.edu/owl/general_writing/grammar/using_articles.html
https://www.englisch-hilfen.de/en/exercises_list/artikel.htm
https://www.english-grammar.at/online_exercises/articles/article3.htm
https://www.english-grammar.at/online_exercises/articles/article2.htm