Did chinese discover America?

There are different theories about the America´s discovery.According to the historian Galvin Menzies, the chinese were the first in exploring the world.He says in his theory, they explored Austria 350years before captain Cook, circled the world, a century before Mgellan, on America shores 71 years before Christopher Columbus. Now well, the  Menzies´s theory can be trusted, becauses i suppose that he did many investigations and colleted a lot of informations too, many people could agree with him about it, with all the details he has given. But we have learnt in the history and it is established that Christopher Columbus discovered America, it means he  and his men were the fisrt in exploring it. To change  that knowledge that people have ,it will be difficult. although i know  the title of the Reading is only a question. In my opinión ,i agee with Menzies, but the history says it was Christopher Columbus  who dicovered America ,  that it is established for centuries , it will not change, if the chinese were who discovered America, unfortunately for them, Christopher Columbus got the attribute.