What happened more than 10, 000 years ago
A woman let fall ______.

reducing the polar bear population.

paying more attention to the earth’’s rising temperatures

reducing carbon dioxide emissions

refreezing the polar ice caps

When lab rats sleep, their brains revisit the maze they navigated during the day, according to a new study (1) yesterday, offering some of the strongest evidence (2) that animals do indeed dream. Experiments with sleeping rats found that cells in the animals’ brains fire in a distinctive pattern (3) the pattern that occurs when they are (4) and trying to learn their way around a maze.

Based on the results, the researchers concluded the rats were dreaming about the maze, (5) reviewing what they had learned while awake to (6) the memories.

Researchers have long known that animals go (7) the same types of sleep phases that people do, including rapid-eye-movement (REM) sleep, which is when people dream. But (8) the occasional twitching, growling or barking that any dog owner has (9) in his or her sleeping pet, there’s been (10) direct evidence that animals (11) . If animals dream, it suggests they might have more (12) mental functions than had been (13) .

"We have as humans felt that this (14) of memory—our ability to recall sequences of experiences—was something that was (15) human," Wilson said. "The fact that we see this in rodents (16) suggest they can evaluate their experience in a significant way. Animals may be (17) about more than we had previously considered."

The findings also provide new support for a leading theory for (18) humans sleep—to solidify new learning. "People are now really nailing down the fact that the brain during sleep is (19) its activity at least for the time immediately before sleep and almost undoubtedly using that review to (20) or integrate those memories into more usable forms," said an assistant professor of psychiatry at Harvard Medical School.

Y

N

NG

正确

错误

can only be acquired after suffering loss.

often generates unacceptable consequences.

is cultivated and developed with personal growth.

is too abstract to be of any practical value.

When lab rats sleep, their brains revisit the maze they navigated during the day, according to a new study (1) yesterday, offering some of the strongest evidence (2) that animals do indeed dream. Experiments with sleeping rats found that cells in the animals’ brains fire in a distinctive pattern (3) the pattern that occurs when they are (4) and trying to learn their way around a maze.

Based on the results, the researchers concluded the rats were dreaming about the maze, (5) reviewing what they had learned while awake to (6) the memories.

Researchers have long known that animals go (7) the same types of sleep phases that people do, including rapid-eye-movement (REM) sleep, which is when people dream. But (8) the occasional twitching, growling or barking that any dog owner has (9) in his or her sleeping pet, there’s been (10) direct evidence that animals (11) . If animals dream, it suggests they might have more (12) mental functions than had been (13) .

"We have as humans felt that this (14) of memory—our ability to recall sequences of experiences—was something that was (15) human," Wilson said. "The fact that we see this in rodents (16) suggest they can evaluate their experience in a significant way. Animals may be (17) about more than we had previously considered."

The findings also provide new support for a leading theory for (18) humans sleep—to solidify new learning. "People are now really nailing down the fact that the brain during sleep is (19) its activity at least for the time immediately before sleep and almost undoubtedly using that review to (20) or integrate those memories into more usable forms," said an assistant professor of psychiatry at Harvard Medical School.

Water shortages in cities.

Earlier thawing of lakes and rivers.

Increased levels of greenhouse gases.

The rapid extinction of the polar bear.