Indicate whether the statement classifies as common knowledge or requires a citation.

1. Due to deforestation, the Amazon has been rapidly decreasing in size since the 1960's.
2. A recent study done by scholars at the Brookings Institute found that the number of people living in poverty in America grew by 12.3 million between 2000 and 2010, so that by the end of 2010, 15% of the population was living under the poverty line.
3. According to the Big Bang model, the initial explosion was produced when an infinitely hot, dense center referred to as a singularity, began to expand, giving rise to the particles that eventually formed into our universe.
4. Researchers have found that dispersants utilized to clean up oil spills can lead to lung damage when airborne particles of these dispersants combine with crude oil and are inhaled.
5. Canada has a federal constitutional monarchy.
6. The Big Bang theory posits that the universe began billions of years ago with an enormous explosion.
7. The APA reference style is mainly used in social sciences, business and nursing.
8. The energy of mixing per site for a binary polymer blend with differing degrees of polymerization can be described through the Flory-Huggins equation.
9. MLA is a common citation style used by students.
10. The cattle sector is responsible for 80% of deforestation in the Amazon.