Answer and Explanation:
1. The capital of Brazil was changed on April 21, 1960 by the president Jucelino Kubitschek, who built a city, called Brazilia, to become the country's federal capital instead of Rio de Janeiro, which was the old capital. He did this because Rio de Janeiro is very close to the ocean and he believed that it left the capital vulnerable to marine attacks, for this reason, he decided to move the capital to a more central region of the country, where it would be more protected.
2. Internal migration in Brazil occurs mainly due to economic factors, where citizens from the poorest states and with the worst living conditions (northeastern states) migrate to the producing centers of the country, which are the southeastern states, mainly São Paulo. Internal migration in China also has the economic condition as its main reason, however the Chinese are constantly migrating to the country's capital and need to submit to a series of laws and guidelines, while in Brazil, this process is done without any type of legislation or restriction.