Depression increases your risk of a number of diseases and other conditions by, for example, increasing levels of stress hormones such as cortisol or adrenaline. Depression can affect the immune system, making it harder for your body to fight infection. Vaccinations are even less effective in people with depression.
The total surface area of the Earth is about 7008510000000000000â 510 million km2 (197 million sq mi). Of this, 70.8%, or 7008361130000000000â 361.13 million km2 (139.43 million sq mi), is below sea level and covered by ocean water.
The United States is the fourth largest country in the world in land area, with 3,678,900 square miles (9,565,140 sq km). The largest country in the world, with 6,592,812 square miles (17,141,311 sq km), is Russia; it is almost twice as big as the United States. Canada ranks number two in size (3,831,000 sq mi/9,960,600 sq km), and China is number three (3,691,500 sq mi/9,597,900 sq km). China and the United States are very similar in size. Related Posts