I think cultural differences make it difficult for poeple from different culture to live together. why? there're several reasons.
　Poeple from different cultures are different in many aspects,from dressing style tothingking.For example, some people regard dressing in that way as being very beautiful according to their culture. However, in other poeple's opinions, that kind of dressing style may be ugly in their cultre.You imagine it's quite difficult for these kinds of poeple mentioned above live together because it would be a nightmare to face someone dressing ugly every day.
what's more,living together needs communication. Poeple from different cultures almost speak different languages.As we all know, there're not so many poeple all over the world master a second foreign language expect their own mother tongues. In that case, how do poeple from different culture communicate freely? Prehaps you may say they can talk by gestures, but another problem comes out.The same gesture in different culture has different ,even opposite meanings.Take shaking one's head as an example,while in China, it means no.In some Arabic contries,it means yes.Threfore, gestures may also cause a lot of trouble. It's not easy for poeple from different culture to exoress their minds clearly to each other, let alone live together.
　In a word,because of culture differences many poeple prefer to living tegether with one from the same culture.