Задайте вопрос, чтобы выяснить недостающую информацию: Before 1 May 2004 there were only ... countries in the European Union. ___ in the European Union before 1 May 2004?
Rewrite the sentences using should, shouldn't, must or mustn't: In Scotland it's a good idea to visit some of the beautiful castles. - In Scotland you ___visit some of the beautiful castles.