How many are there in China bitcoin trading network

2. Bitcoin is a kind of virtual currency in the form of P2P. Point to point transmission means a decentralized payment system. Bitcoin does not rely on specific currency institutions to issue, it is generated through a large number of calculations of specific algorithms. Bitcoin economy uses a distributed database composed of many nodes in the whole P2P network to confirm and record all transactions

3. Okcion, hotcoin, bitcoin China, btctrade, bitera, etc

4. Okcoin and haobtc can be found on the Internet