Most gardeners will probably say gardening
2 . They Consider Rats Lifesavers
When people hear the word “rat”, they may think of dirty animals that spread diseases. And if you are an English learner, you may also connect the word rat with bad expressions. For example, calling someone a rat is a big insult (侮辱) and “rat race” describes a joyless, hurried way of living.
However, the rat trainers at the nonprofit organization, APOPO, see these animals very differently.
Based in Tanzania, APOPO trains a kind of rats to find landmines (地雷). And the rats with their extraordinary sense of smell are very good at the job. APOPO calls their animal team Hero Rats.
Ellie Cutright is an APOPO trainer from Charleston, South Carolina. The researcher shared her very high opinions of rats in a discussion with VOA.
Human beings have used metal-searching devices to do this work for years. But rats — it turns out — do it better. And they also cost less money.
| A．So, rats generally are not beloved animals either in life or in the English language. |
| B．Worldwide there are 110 million hidden landmines left over from wars. |
| C．A rat is an animal that looks like a large mouse with a long tail. |
| D．She wants everyone to know how useful these animals are. |
| E．This kind of rats are large compared to other kinds of rats. |
| F．Cutright explains how the search process (过程) works. |
| G．They consider rats “lifesavers” |
3 . Bright Nights, Big Problems
Astronomers rate the darkness of our skies on a range of 9 (brightest) to 1 (darkest), and most of us spend our lives in the light of levels 5 to 8. All over the globe our nights are growing brighter, and almost nowhere are they growing darker. Studies increasingly link our overuse of light at night with health concerns such as sleep disorders and diseases. Other studies report the damaging ecological consequences and the big waste of energy. But the steady loss of darkness from our lives is not easily measured, for the true value of darkness is something we are barely aware of.
Since the beginning of time, a sky with stars was part of the common human experience. Everywhere on Earth, on most nights, people came face to face with the universe. This experience influenced their beliefs—their very understanding of their place in the world. Today, many of us live under skies which are polluted by light. We live under a night sky showing much fewer stars. Although our night sky continues to shape us, it is the absence of the universe around us that influences our beliefs to create. We are being shaped by a less experience of darkness, and most of us don’t even know what we are missing.
Our Milky Way galaxy is home to several hundred billion stars, and the universe home to several hundred billion other galaxies. A sky with a large number of stars encourages us to emphasize our importance, to imagine humanity as the center of all things. Face to face with the endless size of the universe, we have the chance to know how insignificant we really are. But we also realize the true largeness of our living on this planet, and realize that we have an enormous responsibility to care, that there is no other place to go, that home is here.
“Everyone needs beauty as well as bread,” wrote John Muir, American naturalist. Lighting designers understand that without darkness, there is no “city of light”, and they work constantly to create their city’s atmospheric beauty by mixing artificial light with darkness. And with night’s moonlit geographies, its smells of desert rain and autumn fires, its insect symphonies interrupted by a bird’s call on a lake, natural darkness has many offerings of its own.
Yet we are completely involved in artificial light. Much of this lighting is wholly unnecessary, born of habit and lack of awareness. So let us become aware: simply by keeping our existing lights we could significantly reduce their negative effects on our body, our mind, our soul. Artificial light at night is a wonder, a quality that enriches our lives. But the same has always been true of darkness, and can be again.
1. The author suggests that because of light pollution we ______.| A．tend to come face to face with the universe |
| B．need a lot of imagination to understand the universe |
| C．are considerably less creative than our ancient ancestors were |
| D．experience the world in a different way to previous generations |
| A．We have an over-confident belief in our own value. |
| B．We behave as if nothing exists apart from ourselves. |
| C．We ignore the requirement of looking after our planet. |
| D．We avoid thinking too deeply about our role on Earth. |
| A．To illustrate the boring life at night without artificial light. |
| B．To explain why people think lighting is necessary at night. |
| C．To provide an example of the attractive qualities of night-time. |
| D．To highlight the differences between urban and natural environments. |
| A．clear about the reasons why artificial light is essential |
| B．dissatisfied with people’s lack of interest in artificial light |
| C．willing to draw comparisons between artificial light and darkness |
| D．hopeful that people will become aware of the negative impact of lights |
4 . For a herder (放牧人) in Africa, the hardest part of the job is searching for cattle lost in the bush. But for Andrew, a herder at a farm in Zimbabwe, it's not a problem. Once he spots Toro, he knows the rest of the herd is nearby. That’s because Toro isn’t an ordinary member of the herd. He's a giraffe. In hot weather, cattle rest in the shade under his belly. And because of his height, Toro can spot lions long before they come close to the herd.
Toro's unusual situation came about after his mother was killed by lions. Toro survived the attack, but he was left with no one to protect him or give him milk. About two days later, some herders spotted and rescued him. With the permission of the Department of Wildlife, the herders moved Toro to Andrew's farm. Since giraffes and cattle are both plant-eating animals that live in groups, their behaviors are much the same. Toro was accepted into the herd and wandered among the cattle as they ate grass.
Toro doesn't always behave like the other members of his new herd. Like many kinds of animals, cattle compete for dominance (支配). Standing more than 13 feet tall, Toro is more than three times taller than the biggest bull, But Toro never tries to be ''the boss. ''He is very used to their company, '' Andrew said. When the herd enters the kraal (家畜栏), the cows and bulls push each other. ''But thanks to his height, Toro does not need to join the mess, '' said Andrew.
When asked if Toro would ever be returned to the wild, Munetsi, an officer of the Department of Wildlife said no. ''In the wild, he would find it difficult to be accepted into another herd or defend himself from predators (猎食者),'' he added. ''He seems very much at home and is respected by the cattle.''
1. What was Toro like when the herders found him?| A．He was left alone. | B．He was seriously ill. |
| C．He was lost in the bush. | D．He was fighting with lions. |
| A．He has fought to be the leader. |
| B．He gets along well with the herd. |
| C．He is pushed around by the bulls. |
| D．He stays away from the herd most of the time |
| A．He will be sent back to the wild. |
| B．He will be put into another herd of giraffes. |
| C．He will continue to live together with Andrew. |
| D．He will be trained to fight with the big animals. |
| A．Giraffes under threat in the wild |
| B．A surprising new family for a giraffe |
| C．A new way of herding appearing in Africa |
| D．Moments showing friendship between animals |
5 . Since English biologist Charles Darwin published On the Origin of Species in 1859, scientists have vastly improved their knowledge of natural history. However, a lot of information is still of the speculation, and scientists can still only make educated guesses at certain things.
One subject that they guess about is why some 400 million years ago, animals in the sea developed limbs (肢) that allowed them to move onto and live on land.
Recently, an idea that occurred to the US paleontologist (古生物学家) Alfred Romer a century ago became a hot topic once again.
Romer thought that tidal (潮汐的) pools might have led to fish gaining limbs. Sea animals would have been forced into these pools by strong tides. Then, they would have been made either to adapt to their new environment close to land or die. The fittest among them grew to accomplish the transition (过渡) from sea to land.
Romer called these earliest four-footed animals “tetrapods”. Science has always thought that this was a credible theory, but only recently has there been strong enough evidence to support it.
Hannah Byrne is an oceanographer (海洋学家) at Uppsala University in Sweden. She announced at the 2018 Ocean Sciences Meeting in Oregon, US, that by using computer software, her team had managed to link Homer’s theory to places where fossil deposits (沉积物) of the earliest tetrapods were found.
According to the magazine Science, in 2014, Steven Balbus, a scientist at the University of Oxford in the UK, calculated that 400 million years ago, when the move from land to sea was achieved, tides were stronger than they are today. This is because the planet was 10 percent closer to the moon than it is now.
The creatures stranded in the pools would have been under the pressure of “survival of the fittest”, explained Mattias Green, an ocean scientist at the UK’s University of Bangor. As he told Science, “After a few days in these pools, you become food or you run out of food... the fish that had large limbs had an advantage because they could flip (翻转) themselves back in the water.”
As is often the case, however, there are others who find the theory less convincing. Cambridge University’s paleontologist Jennifer Clark, speaking to Nature magazine, seemed unconvinced. “It’s only one of many ideas for the origin of land-based tetrapods, any or all of which may have been a part of the answer,” she said.
1. Who first proposed the theory that fish might have gained limbs because of tidal pools?| A．Hannah Byrne. | B．Charles Darwin. | C．Steven Balbus. | D．Alfred Romer. |
| A．There were larger oceans. | B．Earth was under greater pressure. |
| C．Earth was closer to the moon. | D．The moon gave off more energy. |
| A．settled | B．trapped | C．abandoned | D．found |
| A．The arguments over a scientific theory. |
| B．The proposal of a new scientific theory. |
| C．Some new evidence to support a previous theory. |
| D．A new discovery that questions a previous theory. |
The giant panda
If you go out to the fields at night in spring or summer, you can hear frogs singing
The frog is a good and useful creature that benefits human beings. They can catch fast-moving
But now frogs
The cause responsible for the rapid
Something must be done without delay
8 . Life in the Clear
Transparent animals let light pass through their bodies the same way light passes through a window. These animals typically live between the surface of the ocean and a depth of about 3,300 feet---as far as most light can reach. Most of them are extremely delicate and can be damaged by a simple touch. Sonke Johnsen, a scientist in biology, says, “These animals live through their life alone. They never touch anything unless they’re eating it, or unless something is eating them.”
And they are as clear as glass. How does an animal become see-through? It s trickier than you might think.
The objects around you are visible because they interact with light. Light typically travels in a straight line. But some materials slow and scatter (散射) light, bouncing it away from its original path. Others absorb light, stopping it dead in its tracks. Both scattering and absorption make an object look different from other objects around it, so you can see it easily.
But a transparent object doesn’t absorb or scatter light, at least not very much. Light can pass through it without bending or stopping. That means a transparent object doesn’t look very different from the surrounding air or water. You don’t see it you see the things behind it.
To become transparent, an animal needs to keep its body from absorbing or scattering light. Living materials can stop light because they contain pigments (色素) that absorb specific colors of light. But a transparent animal doesn’t have pigments, so its tissues won’t absorb light. According to Johnsen, avoiding absorption is actually easy. The real challenge is preventing light from scattering.
Animals are built of many different materials---skin, fat, and more---and light moves through each at a different speed. Every time light moves into a material with a new speed, it bends and scatters. Transparent animals use different tricks to fight scattering. Some animals are simply very small or extremely flat. Without much tissue to scatter light, it is easier to be see-through. Others build a large, clear mass of non-living jelly-like (果冻状的) material and spread themselves over it.
Larger transparent animals have the biggest challenge, because they have to make all the different tissues in their bodies slow down light exactly as much as water does. They need to look uniform. But how they’re doing it is still unknown. One thing is clear: for these larger animals, staying transparent is an active process. When they die, they turn a non-transparent milky white.
1. According to Paragraph 1,transparent animals .| A．stay in groups | B．can be easily damaged |
| C．appear only in deep ocean | D．are beautiful creatures |
| A．silently | B．gradually |
| C．regularly | D．completely |
| A．change the direction of light travel | B．gather materials to scatter light |
| C．avoid the absorption of light | D．grow bigger to stop light |
| A．move more slowly in deep water |
| B．stay see-through even after death |
| C．produce more tissues for their survival |
| D．take effective action to reduce light spreading |
