Passage 1 In 1999, a deadly disease appeared in the United States. There were several incidences that yearof both birds and people becoming sick and dying in New York City, and doctors couldn’t explainwhy. Subsequently, they discovered that the deaths had been caused by the same thing: the WestNile virus, found typically in birds and transmitted by mosquitoes that live in parts of northernAfrica. The process is known as zoonosis. In most cases, our immune systems are not accustomedto these viruses brought by animals, and are unable to stop them before they harm us.
36. What are “zoonotic diseases”?
(A) a diseases that originate in bats
(B) viruses carried by monkeys
(C) animal viruses that infect people
(D) animal viruses that resist treatment