Answer: The Respiratory System:
The respiratory system is the set of organs responsible for the gas exchange between the animal's organism and the environment, that is, pulmonary hematose, making possible the cellular respiration. In terrestrial vertebrates, the respiratory system is essentially formed by two lungs. But in aquatic animals, such as fish and mollusks, the system is based on the gills, whereas in terrestrial arthropods, respiration is ensured by a system of trachea. In unicellular organisms and in some animals, such as sponges and coelenterates, as well as in "plants" (in the sense of the Lineu taxonomy), there is no true respiratory system, and cellular respiration is ensured by direct gas exchange between the body's cells and the environment.
The Letter from Birmingham Jail, also known as the Letter from Birmingham City Jail and The Negro Is Your Brother, is an open letter written on April 16, 1963, by Martin Luther King Jr. The letter defends the strategy of nonviolent resistance to racism. It says that people have a moral responsibility to break unjust laws and to take direct action rather than waiting potentially forever for justice to come through the courts. Responding to being referred to as an "outsider," King writes, "Injustice anywhere is a threat to justice everywhere".
