|A) Spain and portugal||B) Holland and Belgium|
|C) England and Ireland||D) Denmark and Germany|
Holland is also known as Netherlands, which means "Low lands". Dutch Engineers reclaimed considerable part of the seabed by building dykes and pumping out the sea water into canals. Some houses in Holland are below sea level. Belgium has also Low lands bordering the North Sea and dykes are constructed to control the encroachment of the sea.