These three cities should be the top three port cities in the world, and they are all colonies built by the British. Relatively speaking, Singapore opened at 18 19 and Shanghai at 1842. The British should arrive in Hong Kong later, at 1897! Singapore is a very important port with a long history! It has nothing to do with China. I don't know. Shanghai is the largest and earliest British stronghold in China! After liberation, the British were expelled, and the British brought this asset to Hong Kong, and Hong Kong prospered!