Happy Mother's Day!

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Across
  1. 2. Mythical beast (7)
  2. 4. Dedication from Beethoven (3, 5)
  3. 5. It houses a fox (4)
  4. 8. Connecting Banbury to Woodstock (4, 4, 5)
  5. 10. The king of the household (3)
  6. 11. Transparent surface that needs a good clean (7, 5)
  7. 13. Before 15, 30 and 40 (4)
  8. 14. Venice of the North (9)
  9. 19. Blue Canadian (4, 8)
  10. 20. A game ironically not found in the dictionary (10)
  11. 21. Kazuo Ishiguro's remains of this (3)
Down
  1. 1. G-C-E-A (7)
  2. 3. Birthplace of Hugh Laurie (among others) (6)
  3. 5. Who in the world am I?' Ah, that's the great puzzle! (5, 2, 10)
  4. 6. Back to front melodious perching bird (8)
  5. 7. Soft (5)
  6. 9. Alphabetic palindrome (4)
  7. 12. Anagram of a prime minister's surname (5)
  8. 15. a.k.a Abertawe (7)
  9. 16. Songs by John Lennon and Pink Floyd (6)
  10. 17. Rigidly rhythmic (8)
  11. 18. One of the Seven Dwarves and one of the Mister Men (5)