Read the following text. Choose the best word (s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1.10（）

A．little
B．some
C．much
D．enough

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.

usual

complicated

unique

common

Drug use is rising dramatically among the nation’ s youth after a decade of decline. From 1993 to 1994, marijuana use among young people (1) from 12 to 17 jumped 50 percent. One in five high school seniors (2) marijuana daily. Monitoring the Future, which (3) student drug use annually, reports that negative attitudes about drugs have declined for the fourth year in a row. (4) young people see great risk in using drugs. Mood-altering pharmaceutical drugs are (5) new popularity among young people. Ritalin, (6) as a diet pill in the 1970s and now used to (7) hyperactive children, has become a (8) drug on college campuses. A central nervous system (9) , Ritalin can cause strokes, hypertension, and seizures. Rohypnol, produced in Europe as a (10) tranquilizer, lowers inhibitions and suppresses short-term memory, which has led to some women being raped by men they are going out with. (11) taken with alcohol, its effects are greatly (12) . Rock singer Kurt Cobain collapsed from an (13) of Rohypnol and champagne a month before he committed (14) in 1994. In Florida and Texas, Rohypnol has become widely abused among teens, who see the drug as a less expensive (15) for marijuana and LSD. Alcohol and tobacco use is increasing among teenagers, (16) younger adolescents. Each year, more than one million teens become regular smokers, (17) they cannot legally purchase tobacco. By 12th grade, one in three students smokes. In 1995, one in five 14-year-olds reported smoking regularly, a 33 percent jump (18) 1991. Drinking among 14-year-olds climbed 50 percent from 1992 to 1994,and all teens reported substantial increases in (19) drinking. In 1995, one in five 10th graders reported having been drunk in the past 30 days. Two-thirds of high school seniors say they know a (20) with a drinking problem.

poverty,

extinction.

revolution.

evolution.