Only one: North America, from which Mexico belongs to.
Depending on your home country, Mexico is also considered to be part of either Central America or South America. Both instances are incorrect: Central America is not a continent, and South America includes all countries south of Panama (in fact Mexico is bordering Central America's Guatemala and Belize).
The United States of America is bordered by two countries, not continents: Canada and Mexico. To the west of Alaska is Asia, however, not being landlocked, one does not say that they border eachother.
Asia Africa Australia
Europe, Asia, and Africa
Asia, Africa, Europe.
Only two continents border the Red Sea, they are Asia and Africa.
Canada, Mexico, and Russia border the United States.
The two continents are Europe and Africa.
The United States of America, Mexico and Cuba. Al three border the Gulf of Mexico.
There is no answer to that question. There aren't three continents that are part of the US. The United States is a country, it does not have any continents in it. It itself is part of the continent of North America.
The Persian Empire was established in Asia, North Africa and Eastern Europe. That makes three continents. Your other four continents were not involved.
No continents border Antarctica. The continent is surrounded by the Southern Ocean.
Egypt, russia, Mexico