Complex sentence: During the first World War a large shipyard, "Öresundsvarvet" was constructed, but after the war the fast growing of Landskrona slowed, while nearby towns like Helsingborg, Lund and Malmö continued to grow.
Split into simpler sentences: During the first World War a large shipyard, "Öresundsvarvet" was started. But after the war the fast growing of Landskrona slowed down while nearby towns like Helsingborg, Lund and Malmö continued to grow.