Answer:
The European Union was a union of a large number of European countries which was formed for the development purposes of the countries which were a part of the Union.
Since United Kingdom was the major country where all the activities of the union was taking place, the decision of UK leaving the union had an adverse effect on the union. The infrastructure of the other countries was not so developed as compared to UK, so the practices of the union slowed down a little when UK decided to exit.
