Vídeo com explicação: https://www.youtube.com/watch?v=P4U0uLBATZI
Link 1: http://www.englisch-hilfen.de/en/exercises/nouns_articles/article_the.htm
Link 2: http://www.englisch-hilfen.de/en/exercises/nouns_articles/article_the4.htm
Link 3: http://www.englisch-hilfen.de/en/exercises/nouns_articles/article_the3.htm