is an issue of community competence which practical reasons it is advisable to maintain certain responsibilities to be the member states as said these should be restricted in terms 
This is an issue of Community competence on which, for practical reasons, it is advisable to maintain certain responsibilities to be exercised by the Member States, but, as Mr Barrot said, these should be restricted in terms of scope and also time.
This is an issue of Community competence which, practical reasons, it is advisable to maintain certain responsibilities to be the Member States, as said, these should be restricted in terms scope and also time.