clue is - what is that you have 79% in world .. i.e. water more compact - its SEA. because your third word is S your fourth word has to be S.... so you have now "2,3,4 and 5" look for other clue (5,6 and 7) which increase every year. and you know the first word i.e. A. so just say every word starts from A which is three letter... and AGE comes on. Only 1 first word is missing, till now you got - ESSAGE. A 6 year old can say that it has to be a M in first place . So MESSAGE. yyyyyiippppee !!!