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Passage 2             (1) Did you know that you can catch the flu from animals, including pigs and birds? For years, scientists have suspected that pigs are the bridge for new influenza strains because pigs are mixing bowls for viruses, especially pig and bird viruses. Since this viral mix can happen only when animals come in close contact, scientists have believed that new flu strains often emerge first in China because pigs and ducks there often live in close quarters with humans on small family farms. Therefore, pigs can be simultaneously infected with avian (bird), swine (pig), and human forms of the flu, which then mix and match their genes to create new flu varieties that spread from animals to people.             (2) Sometimes these variant forms are deadly. Researchers had a glimpse of just such a nightmare scenario in 1997. An avian flu virus suddenly began infecting people in Hong Kong, igniting what could have been the beginning of a catastrophic pandemic. The trouble began in May 1997, when a three-year-old boy died after becoming infected with an unusual form of the flu virus now known as H5N1. The following November, the new virus, which turned out to be carried in chickens, was back.  In all, eighteen people were infected with the virus. What saved people from disaster was that the virus did not spread from person to person, but only from infected chickens to people.  To avoid disaster, all poultry in Hong Kong had to be destroyed. If that variant of influenza had gotten loose and begun spreading from person to person, it could have wiped out one-third of the earth’s population.

The author’s primary purpose is to ___.

According to this passage, the H5N1virus spread ___.

Which of the following best states the main idea of paragraph 9?

In paragraph 2, the word retention is closest in meaning to ___.

Passage 5             (1) In the late 1700s, slavery in the North became less widespread. In 1774, Philadelphians, among them Benjamin Franklin, organized an anti-slavery society. Pressure from this group and from Quakers resulted in Pennsylvania becoming in the first state to declare slavery illegal in 1780. Soon after, other states followed. Slaves themselves were also very active in challenging human bondage.             (2) Quok Walker of Massachusetts ran away from his master in April 1781 and sought refuge with a friendly neighbor. His master found Walker a few days later and attacked him with a whip. Beaten severely, Walker stood his ground. He sued for his freedom, pointing out that the new state constitution stated that “all men are born free and equal.” The State Superior Court ruled in Walker’s favor in 1783, and this decision signaled the end of slavery in Massachusetts.             (3) Other events followed, and by 1804, every state north of the Ohio River had passed anti-slavery laws.

In paragraph 6, the word vast is closest in meaning to ___.

Which of these events happened LAST?

The spread of the Hong Kong flu virus was prevented by ___.

Use the difference quotient to compute the derivative of the function