"The Japanese islands are very long from North to South."
- "The Japanese islands are very long from North to South."
"the Japanese islands" 「日本列島」"the Japanese archipelago" も言えます。"archipelago" 「列島」・「群島」
"are very long" 「すごく長い」
"from North to South" 「南北に」"from the North to the South" も使えます。