1) Matthew isn't as young as Lucy.
2) Victoria Falls isn't as big as Niagara Falls.
3) The Danube isn't as short as the Thames. ( w Twoim zdaniu brakuje orzeczenia ! Zajrzyj jeszcze raz do podręcznika ;) )
4) Rome isn't as cold as Warsaw.
5) The Pyrenees aren't as high as the Alps.
6) Spain isn't as wet as Wales.