1 . Steve was a seventh grader, a big boy, looking more like a teenager than a 12-year-old. Yet, he went unnoticed — he had been________ every examination since first grade — until Miss Wilma.

In the middle of the first semester of school, the entire seventh grade was________ for basic skills.

“You all did pretty well,” Miss Wilma told the class after going over the________ except for one boy. And it________ my heart to tell you this, but…” she________ , “the smartest boy in the seventh grade is failing my class.” Steve________ his eyes and carefully examined his fingertips.

After that, Steve still wouldn’t do his homework. Even if Miss Wilma________ punished him, he remained________ .     

“Steve, please! I care about you!”________ , Steve got it! “Someone CARES ABOUT ME?!”

One Monday a couple of weeks later, Miss Wilma gave a________ on the weekend homework. Steve________ through the test and was the first to hand in his paper. With a look of________ , Miss Wilma took his paper and began to look it over.

Miss Wilma’s face was in________ shock! She glanced up at Steve, then________ , then up. The smartest boy in the seventh grade had just passed his first test!

From that moment, nothing was the same for Steve. He discovered that not only could he remember and understand________ , but he could translate what he learned into his life. He became________ . After high school, Steve enlisted in the Navy, and he had a(n)________military career. During his naval years, he inspired many young people who might not have________ themselves without him. A________ took place within the heart of a boy all because of one teacher, who________ .

2 . As a popular subject of study among evolutionary ecologists, the three­spined stickleback (三刺鱼) is known for their different shapes, sizes, and behaviours — they can even live in both sea water and fresh water, and under a wide range of temperatures. But what makes that?

The researchers tracked six populations of the fish before and after seasonal changes to their environment, using genome sequencing (基因组测序). Seasonal changes result in great changes in habitat structure and balance of salt and fresh water, and only those fish able to tolerate these rapid changes survive into the next season.

“These changes probably resemble the habitat shifts experienced by stickleback populations during the past 10,000 years, ” says Professor Barrett. “We hope to gain insight into the genetic changes that may have resulted from natural selection long in the past.”

Remarkably, the researchers discovered the evidence of genetic changes driven by the seasonal shifts in habitats, which mirrored the differences found between long-established freshwater and saltwater populations. “These genetic changes occurred in independent populations over a single season, highlighting just how quickly the effects of natural selection can be detected, ” says Professor Barrett, “the findings suggest that we may be able to use the genetic differences to predict how populations may adapt to the environment.”

The research emphasizes the importance of studying species in dynamic environments to gain a better understanding of how natural selection operates. In the further research, they plan to investigate how repeatable the observed genetic changes are, by testing whether they show up year after year. Doing so would demonstrate their ability to reliably forecast the evolutionary future of these populations.

3 . The endangered pandas in the Qinling Mountains might face a new threat: the loss of their food, bamboo, which makes up 99% of their meals.

Adult pandas spend most part of the day eating bamboo and have to take in at least 40 pounds a day to stay healthy. However, a new study published in Nature Climate Change warned that they may soon find their food gone because most of the bamboo in the Qinling Mountains might disappear by the end of the century as a result of rising temperature worldwide.

A team made up of researchers from Michigan State University and the Chinese Academy of Sciences has studied the effects of climate change on the bamboo in the Qinling Mountains. They have found that bamboo is very sensitive to climate changes. “80% to 100% of the bamboo would be gone if the average temperature rises 3.5 degrees worldwide by the end of the century,” said Liu Jianguo, one of the report’s authors.

He added, “This is how much the temperature would rise by 2100 even if all countries will keep their promises in the Paris Agreement. But you know what is happening all around the world.”

In recent years, China has been trying its best to protect the endangered pandas by setting up more and bigger natural reserves.

“But it is far from enough and the endangered pandas need cooperation from the rest of the world, because their future is not just in the hands of the Chinese,” said Shirley Martin from the World Wildlife Fund but not a member of the team.

The Qinling Mountains, in the southwest of China, are home to about 260 pandas. That is about 13% of China’s wild panda population. In addition, about 375 are living in research centers and zoos in China.

4 . Challenging work that requires lots of analytical thinking, planning and other managerial skills might help your brain stay sharp as you age, a study published on Wednesday in the journal Neurology suggests.

Researchers from the University of Leipzig in Germany gathered more than 1,000 retired workers who were over age 75 and assessed the volunteers’ memory and thinking skills through a battery of tests. Then, for eight years, the scientists asked the same group to come back to the lab every 18 months to take the same tests.

Those who had held mentally stimulating, demanding jobs before retirement tended to do the best in the tests. And they tended to lose cognitive (认知的) function at a much slower rate than those with the least mentally challenging jobs. The results held true even after the scientists accounted for the participants’ overall health status.

“This works just like physical exercise,” says Francisca, who led the study. “After a long run, you may feel like you’re in pain and tired. But it makes you fit. After a long day at work — sure, you will feel tired, but it can help your brain stay healthy.

It’s not just corporate jobs, or even paid work that can help keep your brain fit. Francisca points out. A waiter’s job, for example, that requires multitasking, teamwork and decision making could be just as stimulating as any high-level office work. “Running a family household also requires high-level planning and coordinating abilities,” she says. “You have to bring order to the activities of the children and take care of the bills and groceries.”

Of course, our brains can decline as we grow older for lots of reasons — including other environmental influences or genetic factors. Sill, continuing to challenge yourself mentally and keeping your mind busy can help.

7 . Eyes can speak

Much meaning can be conveyed, clearly, with our eyes, so it is often said that eyes can speak.     1    In a bus you may look at a stranger, but not for too long. And if he senses that you are staring at him, he may feel uncomfortable.

The same is true in our daily life. If you are stared at for more than necessary, you will look at yourself up and down to see if there is anything wrong with you.     2    Eyes do speak, right?

Looking too long at someone may seem to be rude and aggressive.     3    If a man stares at a woman for more than 10 seconds and refuses to look away from her, his intentions are obvious. He wishes to attract her attention and let her know that he is admiring her.

However, when two people are engaged in a conversation, the speaker will only look into the listener’s eyes from time to time to make sure that the listener does pay attention to what the former is speaking.     4    If a speaker looks at you continuously when speaking as if trying to control you, you will feel awkward. A poor liar usually exposes himself by looking too long at the victim. He wrongly believes that looking straight in the eye is a sign of honest communication.     5    

Actually, eye contact should be made based on specific relationships and situations.

8 . People have been wondering why elephants do not develop cancer even though they have lifespans(寿命)that are similar to humans, living for around 50 to 70 years.

Now scientists believe they know why. A team at the University of Chicago, US has found that elephants carry a large number of genes that stop tumors(肿瘤)developing. To be precise, they found 20 copies of an anti-tumor gene called TP53 in elephants. Most other species, including humans, only carry one copy.

According to the research, the extra copies of the gene improved the animal’s sensitivity to DNA damage, which lets the cells quickly kill themselves when damaged before they can go on to form deadly tumors.

“An increased risk of developing cancer has stood in the way of the evolution of large body sizes in many animals,” the study author Dr Vincent Lynch told The Guardian. If every living cell has the same chance of becoming cancerous(癌变的),large creatures with a long lifespan like whales and elephants should have a greater risk of developing cancer than humans and mice. But across species, the risk of cancer does not show a connection with body mass.

This phenomenon was found by Oxford University scientist Richard Peto in the 1970s and later named “Peto’s paradox(悖论)”. Biologists believe it results from larger animals using protection that many smaller animals do not. In the elephant’s case, the making of TP53 is nature’s way of keeping this species alive.

The study also found that when the same genes were brought to life in mice, they had the same cancer resistance as elephants. This means researchers could use the discovery to develop new treatments that can help stop cancers spreading or even developing in the first place.

“Nature has already figured out how to prevent cancer,” said Joshua Schiffman, a biologist at the School of Medicine, University of Utah, US. “It’s up to us to learn how different animals deal with the problem so that we can use those strategies to prevent cancer in people.”

Yours sincerely,

Mr Helper