Was there a clear winner in World War I?

Their was no clear winner of world war 1. Some people say that world war 2 was part of world war 1. The above answer is misleading, as it could suggest that an undefeated Germany signed a very damaging peace treaty - which obviously wasn't the case. Moreover, in its present form the answer could be taken to support the 'stab-in-the-back' theory, though I don't think that's the intention. The Central Powers were defeated and two of them - Austria-Hungary and the Ottoman Empire broke up.