A student is writing an informational essay about the impact of global warming on polar bears in the Arctic.

As climate change and the effects of global warming are felt worldwide, scientists have determined that polar bears in the Arctic are just one of the many species facing extinction from our rapidly warming planet. As the ocean waters warm, the main food source for the bears is disappearing. Shortages of food are literally causing these creatures to die of starvation.

Whereas bears could previously walk out onto the sea ice and wait for a seal to poke its snout through, shrinking sea ice means the bears must now walk or swim much farther than they did before to find food. These longer migrations to find food are taking their toll on the bear population.

Seals are a polar bear's main source of protein. They are also another victim of global warming. With the sea ice melting earlier in the warmer springtime and forming later in the warmer winters, seals struggle with finding a safe place to raise their pups. As a result, their numbers are starting to drop, meaning they are also no longer a plentiful food source for the bears

Read the attached passage and then answer this question about it. You are asked to help a student with his conclusion for the attached essay. Which would be the best conclusion option he should use?

A. The effects of global warming and climate change are seen in a chain-reaction in nature. The melting of the ice creates a struggle for the seals as they seek a safe place to raise their young, and with fewer seals that are more difficult to find the polar bears are starving. The ecosystem is all interrelated and global warming shows us just how delicate a balance it is.

B. Polar bears find themselves in a battle with humans over their main food source. With locals killing seals for food and fur, the polar bears are finding it more and more difficult to hunt. We must enact stricter hunting regulations to save the seals, which will, in turn help to save the polar bears.

C. Before the majestic animals of the Arctic become extinct, people must work hard to drop their greenhouse gas emissions, including driving less and recycling more. Only by reversing the damaging effects of greenhouse gasses can the animals of the Artic be saved. We much step up and do our part to help save the planet.

D. Scientists are still working to understand the effects of global warming and climate change. In Australia, as climate change sparks huge and destructive wildfires, the eucalyptus trees native to the area are being destroyed. This, in turn, has a huge impact on another bear, the koala bear.

What is a better way to write this sentence? "Me and Alex went to the movies last weekend and saw a great film by our favorite director Steven Spielberg."

A. "Alex and me went to the movies last weekend and saw a great film by our favorite director: Steven Spielberg."

B. "To see a great film by our favorite director: Steven Spielberg, Alex and me went to the movies last weekend."

C. "Alex and I went to the movies last weekend and saw a great film by our favorite director, Steven Spielberg."

D. "Steven Spielberg is mine's and Alex's favorite director, so we went to the movies last weekend to see a movie by him."

How many terms are in the sequence 0.5, 1, 2 , 4, ..., 256?

A. 8

B. 16

C. 10

D. The answer cannot be determined.

There are 125 adults and children attending a movie in a theatre. The cost for an adult to attend the movie is $5.75 and a child pays 3.50. The theatre raised $617.50 in total sales for the movie. If a represents the number of adults and c represents the number of children that attend the movie, which of the following systems of equations can be used to find the number of adults and children that attended the movie?

A. a + c = 125 5.75a + 3.50 c = 617.50

B. 5.75a + 3.50c = 125 a + c = 617.50

C. a + c = 125 3.50a + 5.75c = 617.50

D. a + c = 617.50 3.50a + 5.75c = 125

A. Option A

B. Option B

C. Option C

D. Option D

What is twice the difference of angles 5 and 2 in the attached figure, if angle 4 measures 55 degrees?

A. 70 degrees

B. 360 degrees

C. 220 degrees

D. 140 degrees

A drug company is evaluating a new method to measure levels of sugar in blood samples. The test is run hundreds of times on samples where the true level of sugar is already known. No test will be perfectly accurate all of the time, but it is

important that the result of any test be as close to the correct value as possible.

Which of these statistical measures will be most helpful in determining if the testing method in the attached description meets this condition?

1.

the mode of the test results

2.

the mean of the test results

3.

the minimum and maximum values of the test results

4.

the standard deviation of the test results

A. 3 and 4

B. 1 and 2

C. 3 only

D. 2 only

Sarah took 8 tests in her history class. Her highest score was 94 and her lowest score was 82.

On the 9th test of the semester, she got a 96.

Using this information, how did her mean score change when the last test was included?

A. It was unchanged

B. It cannot be determined from the given information

C. It increased.

D. It decreased.

Read the text and answer the question.

Blue Crabs Provide Evidence of Oil Tainting Gulf Food

Weeks ago, before engineers pumped in mud and cement to plug the gusher, scientists began finding specks of oil in crab larvae plucked from waters across the Gulf coast.

The government said last week that three-quarters of the spilled oil has been removed or naturally dissipated from the water. But the crab larvae discovery was an ominous sign that crude had already infiltrated the Gulf's vast food web – and

could affect it for years to come.

"It would suggest the oil has reached a position where it can start moving up the food chain instead of just hanging in the water," said Bob Thomas, a biologist at Loyola University in New Orleans.

"Something likely will eat those oiled larvae . . . and then that animal will be eaten by something bigger and so on."

Tiny creatures might take in such low amounts of oil that they could survive, Thomas said. But those at the top of the chain, such as dolphins and tuna, could get fatal "megadoses."

Marine biologists routinely gather shellfish for study. Since the spill began, many of the crab larvae collected have had the distinctive orange oil droplets, said Harriet Perry, a biologist with the University of Southern Mississippi's Gulf Coast

Research Laboratory.

"In my 42 years of studying crabs I've never seen this," Perry said.

She wouldn't estimate how much of the crab larvae are contaminated overall, but said about 40 percent of the area they are known to inhabit has been affected by oil from the spill.

While fish can metabolize dispersant and oil, crabs may accumulate the hydrocarbons, which could harm their ability to reproduce, Perry said in an earlier interview with Science magazine.

She told the magazine there are two encouraging signs for the wild larvae – they are alive when collected and may lose oil droplets when they molt.

Tulane University researchers are investigating whether the splotches also contain toxic chemical dispersants that were spread to break up the oil but have reached no conclusions, biologist Caz Taylor said.

If large numbers of blue crab larvae are tainted, their population is virtually certain to take a hit over the next year and perhaps longer, scientists say. The spawning season occurs between April and October, but the peak months are in July

and August.

How large the die-off would be is unclear, Perry said. An estimated 207 million gallons of oil have spewed into the Gulf since an April 20 drilling rig explosion triggered the spill, and thousands of gallons of dispersant chemicals have been

dumped.

Scientists will be focusing on crabs because they're a "keystone species" that play a crucial role in the food web as both predator and prey, Perry said.

Richard Condrey, a Louisiana State University oceanographer, said the crabs are "a living repository of information on the health of the environment."

Named for the light-blue tint of their claws, the crabs have thick shells and 10 legs, allowing them to swim and scuttle across bottomlands. As adults, they live in the Gulf's bays and estuaries amid marshes that offer protection and abundant

food, including snails, tiny shellfish, plants and even smaller crabs. In turn, they provide sustenance for a variety of wildlife, from redfish to raccoons and whooping cranes.

Adults could be harmed by direct contact with oil and from eating polluted food. But scientists are particularly worried about the vulnerable larvae.

That's because females don't lay their eggs in sheltered places, but in areas where estuaries meet the open sea. Condrey discovered several years ago that some even deposit offspring on shoals miles offshore in the Gulf.

The larvae grow as they drift with the currents back toward the estuaries for a month or longer. Many are eaten by predators and only a handful of the 3 million or so eggs from a single female live to adulthood.

But their survival could drop even lower if the larvae run into oil and dispersants.

"Crabs are very abundant. I don't think we're looking at extinction or anything close to it," said Taylor, one of the researchers who discovered the orange spots.

Still, crabs and other estuary-dependent species such as shrimp and red snapper could feel the effects of remnants of the spill for years, Perry said.

"There could be some mortality, but how much is impossible to say at this point," said Vince Guillory, biologist manager with the Louisiana Department of Wildlife and Fisheries.

Perry, Taylor and Condrey will be among scientists monitoring crabs for negative effects such as population drop-offs and damage to reproductive capabilities and growth rates.

Crabs are big business in the region. In Louisiana alone, some 33 million pounds are harvested annually, generating nearly $300 million in economic activity, Guillory said.

Blue crabs are harvested year-round, but summer and early fall are peak months for harvesting, Guillory said.

Prices for live blue crab generally have gone up, partly because of the Louisiana catch scaling back due to fishing closures, said Steve Hedlund, editor of SeafoodSource.com, a website that covers the global seafood industry.

Fishers who can make a six-figure income off crabs in a good year now are now idled – and worried about the future.

"If they'd let us go out and fish today, we'd probably catch crabs," said Glen Despaux, 37, who sets his traps in Louisiana's Barataria Bay. "But what's going to happen next year, if this water is polluted and it's killing the eggs and the larvae? I

think it's going to be a long-term problem."

Excerpt from "Blue Crabs Provide Evidence of Oil Tainting Gulf Food Web" by John Flesher. Copyright © 2010 by The Associated Press. Reprinted by permission of The Associated Press.

Read the sentence from the text.

The government said last week that three-quarters of the spilled oil has been removed or naturally dissipated from the water.

What does the use of the word dissipated suggest? (Choose two.)

A. Some of the spilled oil has left the Gulf waters.

B. Some of the spilled oil has been made non-toxic.

C. Some of the spilled oil has intensified in strength.

D. Some of the spilled oil has separated into smaller parts.

E. Some of the spilled oil has been consumed by ocean organisms.

Read the text and answer the question.

Blue Crabs Provide Evidence of Oil Tainting Gulf Food

Weeks ago, before engineers pumped in mud and cement to plug the gusher, scientists began finding specks of oil in crab larvae plucked from waters across the Gulf coast.

The government said last week that three-quarters of the spilled oil has been removed or naturally dissipated from the water. But the crab larvae discovery was an ominous sign that crude had already infiltrated the Gulf's vast food web – and

could affect it for years to come.

"It would suggest the oil has reached a position where it can start moving up the food chain instead of just hanging in the water," said Bob Thomas, a biologist at Loyola University in New Orleans.

"Something likely will eat those oiled larvae . . . and then that animal will be eaten by something bigger and so on."

Tiny creatures might take in such low amounts of oil that they could survive, Thomas said. But those at the top of the chain, such as dolphins and tuna, could get fatal "megadoses."

Marine biologists routinely gather shellfish for study. Since the spill began, many of the crab larvae collected have had the distinctive orange oil droplets, said Harriet Perry, a biologist with the University of Southern Mississippi's Gulf Coast

Research Laboratory.

"In my 42 years of studying crabs I've never seen this," Perry said.

She wouldn't estimate how much of the crab larvae are contaminated overall, but said about 40 percent of the area they are known to inhabit has been affected by oil from the spill.

While fish can metabolize dispersant and oil, crabs may accumulate the hydrocarbons, which could harm their ability to reproduce, Perry said in an earlier interview with Science magazine.

She told the magazine there are two encouraging signs for the wild larvae – they are alive when collected and may lose oil droplets when they molt.

Tulane University researchers are investigating whether the splotches also contain toxic chemical dispersants that were spread to break up the oil but have reached no conclusions, biologist Caz Taylor said.

If large numbers of blue crab larvae are tainted, their population is virtually certain to take a hit over the next year and perhaps longer, scientists say. The spawning season occurs between April and October, but the peak months are in July

and August.

How large the die-off would be is unclear, Perry said. An estimated 207 million gallons of oil have spewed into the Gulf since an April 20 drilling rig explosion triggered the spill, and thousands of gallons of dispersant chemicals have been

dumped.

Scientists will be focusing on crabs because they're a "keystone species" that play a crucial role in the food web as both predator and prey, Perry said.

Richard Condrey, a Louisiana State University oceanographer, said the crabs are "a living repository of information on the health of the environment."

Named for the light-blue tint of their claws, the crabs have thick shells and 10 legs, allowing them to swim and scuttle across bottomlands. As adults, they live in the Gulf's bays and estuaries amid marshes that offer protection and abundant

food, including snails, tiny shellfish, plants and even smaller crabs. In turn, they provide sustenance for a variety of wildlife, from redfish to raccoons and whooping cranes.

Adults could be harmed by direct contact with oil and from eating polluted food. But scientists are particularly worried about the vulnerable larvae.

That's because females don't lay their eggs in sheltered places, but in areas where estuaries meet the open sea. Condrey discovered several years ago that some even deposit offspring on shoals miles offshore in the Gulf.

The larvae grow as they drift with the currents back toward the estuaries for a month or longer. Many are eaten by predators, and only a handful of the 3 million or so eggs from a single female live to adulthood.

But their survival could drop even lower if the larvae run into oil and dispersants.

"Crabs are very abundant. I don't think we're looking at extinction or anything close to it," said Taylor, one of the researchers who discovered the orange spots.

Still, crabs and other estuary-dependent species such as shrimp and red snapper could feel the effects of remnants of the spill for years, Perry said.

"There could be some mortality, but how much is impossible to say at this point," said Vince Guillory, biologist manager with the Louisiana Department of Wildlife and Fisheries.

Perry, Taylor and Condrey will be among scientists monitoring crabs for negative effects such as population drop-offs and damage to reproductive capabilities and growth rates.

Crabs are big business in the region. In Louisiana alone, some 33 million pounds are harvested annually, generating nearly $300 million in economic activity, Guillory said.

Blue crabs are harvested year-round, but summer and early fall are peak months for harvesting, Guillory said.

Prices for live blue crab generally have gone up, partly because of the Louisiana catch scaling back due to fishing closures, said Steve Hedlund, editor of SeafoodSource.com, a website that covers the global seafood industry.

Fishers who can make a six-figure income off crabs in a good year now are now idled – and worried about the future.

"If they'd let us go out and fish today, we'd probably catch crabs," said Glen Despaux, 37, who sets his traps in Louisiana's Barataria Bay. "But what's going to happen next year, if this water is polluted and it's killing the eggs and the larvae? I

think it's going to be a long-term problem."

Excerpt from "Blue Crabs Provide Evidence of Oil Tainting Gulf Food Web" by John Flesher. Copyright © 2010 by The Associated Press. Reprinted by permission of The Associated Press.

Read the sentence from the text.

Scientists will be focusing on crabs because they’re a “keystone species” that play a crucial role in the food web as both predator and prey, Perry said.

Which statement best describes what the phrase keystone species adds to the meaning of the text?

A. It emphasizes the strength and durability of the blue crabs' outer shells.

B. It emphasizes the mystery and uncertainty of blue crabs' future in the Gulf.

C. It emphasizes the importance of the blue crabs' role in the Gulf's ecosystem.

D. It emphasizes the blue crabs' ability to survive the threats to their environment.