Abstract nouns. Key

1 astonishment / 2 death / 3 developments / 4 disappearance / 5 discovery / 6 loss / 7 permission / 8 behaviour / 9 laughter / 10 embarrassment / 11 pleasure / 12 signature / 13 complaint / 14 announcement / 15 pronunciation / 16 success / 17 arrival / 18 performance / 19 argument / 20 happiness / 21 violence / 22 heat / 23 patience / 24 similarities / 25 sympathy / 26 self-confidence / 27 probability / 28 height