.
https://todayschool.es/grammar/grammar-practice-let-and-be-allowed-to/
http://www.focus.olsztyn.pl/en-make-let-allow-exercises.html#.Wz5vu9JKjIU
https://www.perfect-english-grammar.com/let-or-make-exercise-1.html
http://www.esl-lounge.com/student/grammar/3g77-intermediate-make-let-allow-reordering.php
http://perso.wanadoo.es/autoEnglish/gr.allow.p.htm
https://www.usingenglish.com/quizzes/334.html
https://www.tolearnenglish.com/exercises/exercise-english-2/exercise-english-72879.php