https://www.perfect-english-grammar.com/indirect-questions-exercise-1.html
https://www.perfect-english-grammar.com/indirect-questions.html
http://www.focus.olsztyn.pl/en-english-indirect-questions-exercises.html#.XNRDMBQzaM8
https://www.e-grammar.org/indirect-question/test1-exercise1/
https://www.ego4u.com/en/cram-up/grammar/question-tags
https://www.englisch-hilfen.de/en/exercises_list/fragen.htm
https://www.english-4u.de/en/grammar-exercises/question-words.htm
https://www.english-4u.de/en/grammar-exercises/question-words2.htm
https://www.english-4u.de/en/grammar-exercises/question-tags.htm
https://www.liveworksheets.com/worksheets/en/English_as_a_Second_Language_(ESL)/Question_words/Question_words*_multiple_choice_hl497xh
https://www.liveworksheets.com/worksheets/en/English_as_a_Second_Language_(ESL)/Question_words
https://drive.google.com/open?id=1dY0MGtEWBYBJOJp7PLYRl4pw9kRheOWZ8s_S7c4ye5Q
https://drive.google.com/open?id=1jXqGRq4DmCuJlpfWPBHSv1bD2j_MFPanPux-wtKqLkk