About geography. Waiting online.

1. Shanghai-Houston: Shanghai-Pacific-Panama Canal-Caribbean-Gulf of Mexico-Houston

2. new york-Yokohama: new york-Atlantic-Caribbean-Panama Canal-Pacific-Yokohama (you can walk the Atlantic backwards).

3. Mumbai-Rotterdam: Mumbai-Arabian Sea-Gulf of Aden-Red Sea-Suez Canal-Mediterranean Sea-Strait of Gibraltar-Atlantic Ocean-Rotterdam

4. Hong Kong-London: Hong Kong-South China Sea-Malacca Strait-Indian Ocean-Gulf of Aden-Red Sea-Suez Canal-Mediterranean-Gibraltar Strait-Atlantic-London.

5. Busan-Rotterdam: Busan-East China Sea-South China Sea-Malacca Strait-Indian Ocean-Gulf of Aden-Red Sea-Suez Canal-Mediterranean Sea-Gibraltar Strait-Atlantic Ocean-Rotterdam.

6. Guangzhou-Melbourne: Guangzhou-South China Sea-Sulawesi Sea-Arafura Sea-Coral Sea-tasman sea-bass strait-Melbourne.

None of the above routes is unique. My writing is more optimized. )

When you say continental bridge transportation, you mean land transportation-theoretically, 4.5 pairs of railways can be used (Eurasian Continental Bridge: Lianyungang-Rotterdam).

I hope it helps you.