Frankly, China was already rich even before the reversion of Hong Kong in '97, and Singapore is a republic, ie. another country. Politically, it has nothing to do with China. Culturally, there are a lot of Chinese that live there, and it is one of the hot spots for Chinese prostitutes. Their spoken language is a conglomeration of English, Malay, Mandarin and Tamil.
It's mostly coastal and industry cities (and surroundings) that make China rich. Guangzhou and Shanghai to name a few big time harbour cities. Whereas Beijing is basically the financial centre of China, it certainly has the most companies located there (within China) that can be considered "global corperations". Hong Kong doesn't really make China rich, because they aren't really under the PRC goverment yet. It has its own economy. Very simple list of cities: http://en.wikipedia.org/wiki/List_of_cities_in_China
