【推荐2】Caleb Arnold loves birds-especially hummingbirds. The 7-year-old boy knows a lot about his favorite animal. "They pollinate(授粉)plants, and they' re pretty and small," he says. But there's one thing Caleb didn't know: hummingbirds see a wider range(范围)of colors than we do.

It makes sense that Caleb didn't know this. Few people did for sure, until June 15,2020, when researchers published a report in Proceedings of the National Academy of Sciences. It confirmed the fact that scientists have long suspected. Birds are experiencing a more colorful world that is above our own. A team of scientists conducted a three-year experiment to find out if hummingbirds are able to tell apart colors that look the same to humans.

To understand the experiment, it¹ s important to know how color vision works. There are three types of tiny color-sensitive cones(锥细胞)in the human eye. Birds, and some other animals, have a fourth. This means they can also see ultraviolet (紫外线)colors. The ultraviolet cone type allows birds to see combination colons that humans can't, like ultraviolet green and ultraviolet red. Biologists studying birds have supposed that birds can see these, but it's been challenging to test this idea.

That's exactly what the team did. They put two bird feeders in the wild. One contained ordinary water. The other contained sugar water. Both feeders held a specially designed LED light stick—sort of a bird-vision light tube-that changed colors. If we are showed the ultraviolet green tube and the green tube, they'd bog just look. green to us. But the hummingbirds saw the difference. They could even tell apart two shades of ultraviolet red. The scientists observed that the birds were able to use the colors of the lights to find the sweet water

Caleb is glad scientists want to better understand birds. Good. is “Good" he said, after hearing the news, "They part of nature.”

1. What is the purpose of the first paragraph?

A．To introduce hummingbirds	B．To describe a boy who loves birds.
C．To lead in the topic of the text.	D．To explain a natural law.

2. What is unknown to most people about hummingbirds?

A．They look very beautiful	B．They are of a small size.
C．They are helpful to plants.	D．They see more colors than humans.

3. What is paragraph 3 mainly about?

A．The reason for birds' better color vision.	B．They are of a small size.
C．Combination colors unseen by humans	D．The experiment to test ultraviolet colors.

4. How did hummingbirds find the water they liked?

A．By tasting the water in the two containers.

B．By recognizing the light colors on the feeders.

C．By smelling the water in different tubes.

D．By telling apart the depth of water in different feeders.

【推荐3】Dogs wag (摇摆) their tails in different directions depending on whether they are excited and wanting to move forward or threatened and thinking of moving back, a study has found.

Researchers in Italy examined the tail wagging behavior of 30 dogs, catching their responses to a range of stimuli (刺激物) with video cameras. To conduct the study they chose 15 male dogs and 15 female ones aged between one and six years. The dogs were all family pets whose owners had allowed them to take part in the experiment at Bari University. The dogs were placed in a large wooden box with an opening at the front to allow for them to view various stimuli. They were tested one at a time.

The researchers led by Professor Giorgio Vallortigara of the University of Trieste found that when the dogs were shown their owners—a positive experience—their tails wagged energetically to the right side. When they were shown an unfamiliar human they wagged to the right, but with somewhat less enthusiasm. The appearance of a cat again caused a right-hand side wag, although with less intensity again. The appearance of a large unfamiliar dog, similar to a German shepherd, changed the direction of tail wagging to the left. Researchers thought the dog was thinking of moving back. When the dogs were not shown any stimuli they tended to wag their tails to the left, suggesting they preferred company. While the changes in the tail wagging were not easily noticed without the aid of video, it was thought that the findings could help people judge the mood of dogs. Computer and video systems, for example, could be used by professional dog trainers to determine the mood of dogs that they were required to approach.

1. The video cameras were used to catch the dogs’ responses because________.

A．it was easier to catch the dogs’ response changes in the tail wagging

B．the dogs were put in the wooden boxes and tested one at a time

C．they enabled the dogs’ owners to know about their dogs’ habit

D．the dogs wagged their tails in different directions when they were in different moods

2. The underlined word “intensity” in paragraph 3 means________.

A．surprise

B．worry

C．excitement

D．interest

3. When there are no stimuli, a dog will ________.

A．wag to the left	B．wag to the right
C．not wag at all	D．wag to the left and then to the right

4. The purpose of doing the experiment is ________.

A．to train dogs for their owners	B．to help people judge the mood of dogs
C．to help dogs find company	D．to help people choose their pet dogs

【推荐3】Antarctica is known for being a vast land of ice and snow, a place too cold for most life. Despite this, the continent is slowly starting to turn warm. According to the Guardian, the Antarctic has registered a new high temperature for the first time on record, prompting fears of climate instability in the world’s iciest place.

On Feb 9, Brazilian researchers at Seymour Island reported a temperature of 20.75℃ on the icy continent of Antarctica. It was almost a full degree higher than the previous record of 19.8℃, taken on Signy Island (西格尼岛) in January 1982.

This record-breaking reading was taken at a monitoring station in the northern part of Antarctica. According to Brazilian soil scientist Carlos Schaefer, the temperature was documented during a 20-year-long research project. The focus of this project is to study the effect that climate change has on the permafrost (永久冻土) within the region. Permafrost is soil that stays frozen for at least two years. Although this is a first record high for Antarctica, Schaefer stressed that “We can’t use this to anticipate climatic changes in the future. It’s simply a signal that something different is happening in that area.”

But in fact, the last high temperature reading was in the 19℃ range. These higher temperatures can cause ice and glaciers in Antarctic regions to melt. The Antarctic peninsula (半岛)--the long finger of land that stretches towards Argentina--is most dramatically affected. Scientists saw glaciers that have retreated by more than 100 meters in Discovery Bay where the snow melted in little more than a week, leaving dark exposed rock. This melted ice leads to a rise in sea levels that can threaten the safety of coastal areas. It’s believed to be behind an alarming decline of more than 50 percent in chinstrap penguin (帽带企鹅) colonies, which are dependent on sea ice.

Like American writer Ernest Hemingway once said, “The Earth is a fine place and worth fighting for.” We should do everything we can to help save our planet. Otherwise, it may become too hot for us to fix.

1. What did Brazilian researchers report on Feb 9?

A．Seymour Island is the warmest region in the Antarctic.

B．Antarctica hit a record high temperature of 20.75℃.

C．The average temperature of Antarctica ranges from 19.8℃ to 20.75℃.

D．Antarctica’s new record temperature is a full degree higher than the previous decade.

2. What’s the main purpose of the 20-year-long research project?

A．To predict possible climatic change in the future.

B．To monitor Antarctica’s contributions to world climate change.

C．To explain why the permafrost may cause glaciers to melt.

D．To examine how the permafrost is influenced by climate change.

3. What does the underlined word “retreated” probably mean?

A．moved backward.	B．increased in size.
C．covered a certain area.	D．stretched in an opposite direction.

4. What is the main idea of the last paragraph?

A．The Earth will be hotter and hotter.

B．The high temperature can cause ice in Antarctica melt.

C．People should spare no effort to protect the earth and the environment.

D．A rise in sea levels can threaten the safety of coastal areas.

【推荐1】Scientists say baby sharks are at risk of being born smaller and without the energy they need to survive because of warming oceans from climate change.

Scientists working with the New England Aquarium in Boston, Massachusetts studied epaulette sharks. They found that warmer conditions sped up the sharks’ growing process. That meant the sharks were born earlier and very tired.

John Mandelman is vice president and chief scientist of the Anderson Cabot Center for Ocean Life at the New England Aquarium. He said it is widely believed that epaulette sharks are “hardy,” or able to survive difficult conditions. “What it means is this very resilient species is more vulnerable than we thought, and this could be true of other sharks,” he added.

The scientists studied 27 sharks using the New England Aquarium’s reproduction program. Some were raised in average summer water temperatures, about 27 degrees Celsius. Others were raised in higher temperatures around 29 degrees Celsius and 31 degrees Celsius. They found that the sharks raised in the warmest temperatures weighed much less than those raised in average temperatures. They also showed reduced energy levels.

Epaulette sharks can grow to a length of about one meter. Their name comes from large spots on their bodies that look like decorations on some military clothing. The sharks are listed as stable and a species of “least concern” on the International Union for Conservation of Nature Red List of Threatened Species.

One study this year found that worldwide numbers of oceanic sharks and rays dropped more than 70 percent between 1970 and 2018. Overfishing is a main concern, while climate change and pollution also threaten sharks. Mariah Pfleger is an ocean scientist at the protection group Oceana. She said the study should serve as a warning to ocean governing agencies that careful supervision is needed to prevent the loss of more sharks. “This study further exemplifies that sharks will not be immune to a warming ocean,” Pfleger added.

1. The new study shows us that warming oceans may lead to baby sharks’         .

A．later birth and less weight.

B．later birth and more weight.

C．earlier birth and less weight.

D．earlier birth and more weight.

2. Which is not the reason for the dropping number of oceanic sharks in the last 50 years?

A．Climate change.

B．Pollution.

C．Overfishing.

D．Supervision.

3. From the text, what can we know about epaulette sharks?

A．They can grow to about one centimeter in length.

B．They are named after their body characteristics.

C．They are least endangered species.

D．They are able to survive all kinds of conditions.

4. What’s Mariah Pfleger’s attitude towards the study?

A．Positive.

B．Negative.

C．Indifferent.

D．Arbitrary.

【推荐2】A study has found that smiling at London bus drivers increases their happiness. The finding feels obvious and unexpected at the same time. For decades, passengers and drivers in London greet each other in an unfriendly mood; any affection feels disgust. While, the authors of the research, which was conducted by the University of Sussex and others, hope it will lead to “more interaction and kindness on buses”. However, Londoners are sceptical.

It might seem impossible that a report on London’s buses could change behaviour. But it has happened before. London’s buses have an underappreciated role in the history of medical science. In the 1940s, a single study of London’s transport workers transformed epidemiology(流行病学), medicine and the way we live now. Every time you go on a run, check your steps, or take the stairs instead of the lift, you are following a path established by the feet of the workers on London’s buses.

In the late 1940s, Britain, like many rich countries, was suffering from an “epidemic” of heart disease and no one knew why. Various hypotheses (猜想), such as stress, were suggested; but no one noticed exercise. The idea that health and exercise were linked “wasn’t the accepted fact that we know today”: Some even felt that “too much physical activity was a bad thing for your health”.

At this time, Jerry Morris started to suspect that the too many deaths from heart disease might be linked to occupation. He began studying the medical records of 31,000 London transport workers. His findings were breathtaking: conductors, who spent their time running up and down stairs, had an approximately 30% lower incidence of disease than drivers. He also looked at postal workers, and found a similar pattern: postmen had far lower rates of disease than telephonists.

Morris’s research was eventually published in 1953, and his work had consequences both big and small. Morris now took up exercise, handing his jacket to his daughter and just running. “People initially thought I went bananas.” But slowly, the rest of the world took off its jacket and followed.

1. What impact did the study of London’s transport workers in the 1940s have on the field of medicine?

A．It led to the discovery of a new virus.

B．It proved the main cause of heart disease.

C．It showed the relationship between exercise and health.

D．It corrected the misunderstanding of London bus drivers.

2. How did Morris conduct his study?

A．By carrying out a survey.	B．By study their occupation.
C．By analyzing the medical data.	D．By doing medical examination.

3. What’s the meaning of “went bananas” in the last paragraph?

A．Falling ill.	B．Saving energy.
C．Starting running.	D．Becoming crazy.

4. Which can be the best title of this passage?

A．How to Increase Drivers’ Happiness

B．How to Transform the Way We Live

C．How Exercise Influenced Heart Health

D．How London Bus Drivers Led the World to Exercise

【推荐3】Sure, it's good to get along with your teacher because it makes the time you spend in the classroom more pleasant. And yes, it's good to get along with your teacher because, in general, it's smart to learn how to relate to the different kinds of people you'll meet throughout your life.

But really, there's one super-important reason why you should get along with your teacher. When you do, "learning bursts right open," says Evelyn Vuko, a longtime teacher who writes an education column called "Teacher Says" for the Washington Post newspaper.

In fact, kids who get along with their teachers not only learn more, but they're more comfortable asking questions and getting extra help. This makes it easier to understand new material and do your best on tests. When you have this kind of relationship with a teacher, he or she can be someone to turn to with problems, such as problems with learning or school matters, such as bullying (欺凌弱小者). 

As a kid in a primary or middle school, you're at a wonderful period in your life. You're like a sponge (海绵), able to soak up lots of new and exciting information. On top of that, you're able to think about all this information in new ways. Your teacher knows that, and in most cases, is very excited to be the person who's giving you all that material and helping you put it together. Remember, teachers are people, too, and they feel great if you're open to what they're teaching you. That's why they wanted to be teachers in the first place---to teach!

Some kids may be able to learn in any situation, whether they like the teacher or not. But most kids are sensitive (敏感的) to the way they get along with the teacher, and if things aren't going well, they won't learn as well and won't enjoy being in class.

1. What does the writer mainly talk about in the passage? ________

A．How much the students are expected to get along with teachers.

B．How to make the time in the classroom more pleasant.

C．How important to have a good relationship with teachers.

D．How to get a long well with teachers.

2. What does "turn to" in the third paragraph really mean? ________

A．get help from

B．take hold of

C．look for

D．think about

3. According to the passage, which of the following can be inferred? ______

A．If you have a good relationship with your teacher, you can get more help and learn more   knowledge.

B．If you find it comfortable to ask questions, you can build a good relationship with teachers.

C．If you are getting on well with your teachers, you have more problems than others.

D．If you do your best on tests, you can build a good relationship with teachers.

4. Which is Not True on teachers and their work according to the passage? ______

A．There are some students who can learn even if they don't like the teacher.

B．Having a bad relationship with teachers does some harm to your studies.

C．Teachers are excited even if you wouldn't like to accept their teaching.

D．Teachers sometimes have the same feelings as students do.