a) language-in china, most people could speak Putonghua. However in Europe, the are many language existing (e.g.: French, German, Italian, etc). for instance: it is difficult of people of different nationality to communicate withe ach other.
b) appearance-chinese have 'yellow skin' but the skin color of european varies.
c) history-chinese history is constant of most people have no conflicts because their historical backgrounds are similar. for europeans, they have different national backgrounds which may even lead to discrimination and disputes