对：what are some of the positive and negative effects of non-

Britain already is a country with a large number of foreign nationalities,races,cultures and religions.Their integration is a challenge for the British society.The situation has become even more challenging after the emergence of islamophobia.
Negative effects:In general,immigrants have often been seen as a burden or a threat.
Positive effects:Otherwise,immigrants have done more to contribute to the country's economy.