A drug has stopped brain deterioration in Alzheimer’s（早老性痴呆病）, patients for the first time, scientists announced yesterday.

Mental decline was stopped for 18 months in some patients, in results described as (21)______ (strong) sign yet that an effective treatment for the disease is near. Researchers said that the drug — (22)______ (take) as a tablet twice a day — could soon become the first medicine given to Alzheimer’s patients to keep the disease at bay for as long as possible.

The final-stage trial had at first appeared (23)______ (be) a failure as the drug did not work in patients who were taking other dementia（痴呆，精神错乱） medicines. (24)______, among the 15 per cent of 891 patients not taking other medicines, the drug appeared to have remarkable effects.

These patients say no drop-off in their reasoning and memory skills over 18 months, nor in their ability to carry out everyday tasks.

 (25)______, key areas of their brain shrank a third less than other patients in the trial, researchers told the Alzheimer’s Association International Conference in Toronto.

“There is a pattern of disease modification here,” Serge Gauthier, of McGill University, (26)______ presented the results, said. “This is the first time it (27)______ (happen) in our field that a drug reduces the rate of brain atrophy（萎缩）.”

At present patients are prescribed drugs such as donepezil, which help to control symptoms for a time but do not stop worsening damage to the brain.

Doctor Gauthier said it was a surprise (28)______ other dementia drugs appeared to cancel out the effects of the new drug, called LMTX or LMTM, but (29) _______that just as cancer patients were given some medicines initially and then switched (30)______ _______ those stopped working, so Alzheimer’s patients could be given LMTX as a first-choice drug.

“I’m excited about the promise of LMTX,” he said.

A. investment  B. curriculum  C. gains      D. involved     E. scale      F. matters

G. push       H. positive     I. weigh      J. copied       K. attention

Preschool is getting a lot of attention these days. President Obama and mayors across the country are touting（标榜）preschool as an important investment in the economy.

As policymakers _31_ the costs and benefits of “preschool for all,” they’re trying to figure out what actually works in the classroom.

School officials say the system of intensive coaching is a key to classroom success. Boston uses coaches for teachers as part of its larger _32_ for preschool quality. The district has installed a strict _33_ and requires teachers to get masters degrees.

Academics have known for some time that quality _34_, but much of the research has focused on small-scale programs. The Boston program is different.

Last year, a Harvard University study found big _35_ in math and vocabulary in Boston after the program, where the preschool system spans 68 schools.

“That you can develop high quality across 68 schools was not obvious,” says Harvard economist and education professor Richard Murnane, who was not _36_ in the study. “We can do better in preparing poor children for school, and it can be done at considerable _37_.”

But not everyone is sold. Some preschool research shows academic gains disappearing by third grade. Critics say a program without staying power is hardly worth a big public _38_.

“So we just don’t know about Boston, whether the _39_ effects that are talked about at the end of the pre-K year are going to be there at the end of first grade, second grade or third grade,” Whitehurst says. “Without knowing that, it’s hard to make a decision about whether this is a great program that ought to be _40_ in other places.”

But policymakers around the country aren’t waiting for a long-term study. They’re coming to Boston to see the preschool program up close.

A. Dr Rogers gets round this by using a different material for each layer of the stack.

B. The technology continues to pop up in new devices all the time, from sunglasses to electric vehicle charging stations.

C. But many scientists would like to replace it with something fundamentally better.

D. Suitably improved, Dr Rogers reckons, their efficiency could rise to 50%.

E. The hope for a “solar revolution” has been floating around for decades.

F. The band gap defines the longest wavelength of light a semiconductor can absorb (it is transparent to longer wavelengths).

Sunlight is free, but that is no reason to waste it. Yet even the best silicon solar cells – by far the most common sort – convert only a quarter of the light that falls on them. Silicon has the merit of being cheap: manufacturing improvements have brought its price to a point where it is snapping at the heels of fossil fuels.  67. ______

John Rogers, of the University of Illinois, Urbana-Champaign, is one. The cells he has devised can convert 42.5% of sunlight.  68. ______  Their secret is that they are actually not one cell, but four, stacked one on top of another.

Solar cells are made of semiconductors, and every type of semiconductor has a property called a bank gap that is different from that of other semiconductors.  69. ______  It also fixes the maximum amount of energy that can be captured from shorter wavelength. The result is that long-wavelength photons are lost and short-wave ones incompletely utilized.

70. ______ He chooses his materials so that the bottom of the band gap of the top layer matches the top of the band gap of the one underneath, and so on down the stack. Each layer thus chops off part of the spectrum, converts it efficiently into electrical energy and passes the rest on.

The problem is that the materials needed to make these semiconductors are costly. But Dr Rogers has found a way to overcome this. Normal solar-cell modules are completely covered by semiconductor, but in his only 0.1% of the surface is so covered. The semiconducting stacks, each half a millimeter square, are scattered over that surface many dots. Each stack then has a pair of cheap glass lenses mounted over it. These focus the sun’s light onto the stack, meaning that all incident light meets a semiconductor.

Stress for a teenager is as real a problem as stress for an adult. Therefore, it’s important to understand the causes of stress in teenagers.

   When parents change their jobs or if the family decides to move to a different place, the child has to change schools, find new friends, adapt to the new social circle and fit into new groups. It is always difficult for children to adapt to such changes, which can be a serious cause of stress in their life.

Academic difficulties, such as inability to understand a certain subject can cause stress. Not every child has the ability to understand every subject. Some kids need extra help besides school work to grasp a few concepts. Poor academic performance is often laughed at and is looked down upon by both teachers and peers. In such cases, it can make the child feel isolated, neglected and hurt. All of this, put together, can add to stress, which many times worsens grades.

Extra curricular activities (课外活动) such as playing a sport, or attending art classes can weigh heavily on your child’s mind. Balancing school and extra curricular activities does seem like a burden when you have to be outstanding at both. When the pressures from both the ends get unmanageable, teenagers tend to get tired and annoyed. Tiredness sets in, leading to stress related issues such as lack of concentration in school.

These are the common causes of stress in teenagers, which can be noticed through signs such as poor memory, anxiety, negative and pessimistic attitude. If the signs of teenage stress go unrecognized for a long time, it can make the child emotionally out of balance. And next step, if this happens, it is necessary for parents to know how to deal with stress.

Directions: Translate the following sentences into English, using the words given in the brackets. (15%)

1.       自开业以来，上海迪斯尼乐园天天游人如织。(full)

2.       多吃水果，你就不用担心缺少维生素。(lack)

3.       他似乎在全神贯注地读着今天报纸末版上的体育新闻。(absorb)

4.       尽管Alpha Go在最近的比赛中胜出，但我还是坚定认为人工智能不可能取代人脑。（possibility）