GRAMMAR: https://www.examenglish.com/grammar/b1_grammar.html
http://www.englishtag.com/tests/level_test_intermediate_B1.asp
http://www.englishjet.com/english_courses_files/test_intermediate.asp
3rd Conditional:
https://www.perfect-english-grammar.com/third-conditional-exercise-1.html
https://agendaweb.org/verbs/conditional-third-exercises.html
LISTENING: https://www.examenglish.com/PET/pet_listening_part1.htm
https://learnenglishteens.britishcouncil.org/skills/listening/intermediate-b1-listening
https://www.examenglish.com/B1/index.php
https://www.flo-joe.co.uk/preliminaryenglish/
https://www.examenglish.com/PET/pet_grammar.htm
http://teacherlucia.wikispaces.com/PET+Sentence+Transformation
http://www.englishaula.com/en/pet-exam-writing-cambridge-preliminary-english-test-video-lessons-practice-tests-exercises.php
http://www.autoenglish.org/PET/PETWritingPart1.htm
