Complex sentence: Among his greatest accomplishments is the Czechoslovak Pavilion for the Exposition internatale des art decoratifs et industriels modernes in Paris of 1925; he was awarded the Grand Prize for that design.
Split into simpler sentences: Among his greatest accomplishments is the Czechoslovak Pavilion for the 1925 Exposition internationale des arts décoratifs et industriels modernes in Paris. He was awarded the Grand Prize for that design.