1 . Endangered polar bears are breeding (繁殖) with grizzly bears (灰熊), creating “pizzly” bears, which is being driven by climate change, scientists say.
As the world warms and Arctic sea ice thins, starving polar bears are being forced ever further south, where they meet grizzlies, whose ranges are expanding northwards. And with that growing contact between the two come increasing hybrids (杂交种).
With characteristics that could give the hybrids an advantage in warming northern habitats, some scientists guess that they could be here to stay. “Usually, hybrids aren’t better suited to their environments than their parents, but these hybrids are able to search for a broader range of food sources,” Larisa DeSantis, an associate professor of biological sciences at Vanderbilt University, told Live Science.
The rise of “pizzly” bears appears with polar bears’ decline: their numbers are estimated to decrease by more than 30% in the next 30 years. This sudden fall is linked partly to “pizzly” bears taking up polar bears’ ranges, where they outcompete them, but also to polar bears’ highly specialized diets.
“Polar bears mainly consumed soft foods even during the Medieval Warm Period, a previous period of rapid warming,” DeSantis said, referring to fat meals such as seals. “Although all of these starving polar bears are trying to find alternative food sources, like seabird eggs, it could be a tipping point for their survival.” Actually, the calories they gain from these sources do not balance out those they burn from searching for them. This could result in a habitat ready for the hybrids to move in and take over, leading to a loss in biodiversity if polar bears are replaced.
“We’re having massive impacts with climate change on species,” DeSantis said. “The polar bear is telling us how bad things are. In some sense, “pizzly” bears could be a sad but necessary compromise given current warming trends.”
1. Why do polar bears move further south?| A．To create hybrids. | B．To expand territory. |
| C．To relieve hunger. | D．To contact grizzlies. |
| A．Broader habitats. | B．More food options. |
| C．Climate preference. | D．Improved breeding ability. |
| A．A rare chance. | B．A critical stage. |
| C．A positive factor. | D．A constant change. |
| A．Polar bears are changing diets for climate change. |
| B．Polar bears have already adjusted to climate change. |
| C．“Pizzly” bears are on the rise because of global warming. |
| D．“Pizzly”bears have replaced polar bears for global warming. |
2 . China’s first overpass for wildlife migration has already come into use. The bridge
It’s about two years since the national highway
Those passageways, with a total
3 . The Ethiopian wolf is one of the world's most endangered members of the wolf and dog family. Fewer than 500 survive, living in six small highland areas of Ethiopia. Like other wolves, they form groups that protect their homes and raise their young. That is where the similarity to other wolves ends. Most wolf species work together to hunt. Ethiopian wolves split up in the morning, and each wolf heads out on its own in search of small animals.
The wolves seem to have a special love for the African giant mole-rat. This animal lives only in the Bale Mountains. Most mole-rats feed on roots underground, but the giant mole-rat also searches for food aboveground.
Ethiopia has a rapidly growing human population, and land for farming is short. People are moving into the highlands, driving out wolves and other animals. The wolves face other threats, too. Domestic dogs carry rabies (狂犬病) and other diseases. In some years, these diseases have killed more than three quarters of the wolves in the Bale Mountains. Wolves also have been hit by cars and shot by people.
Since 1995, the Ethiopian Wolf Conservation Programme (EWCP) has worked with local people to learn about and protect the wolves. One of its most important projects has been to vaccinate (接种疫苗) wolves and thousands of domestic dogs against rabies. Another project has been to build stoves (炉子) that burn less fuel. Many people who live near the wolves collect firewood for cooking and heating. When using better stoves, the people collect less firewood — and protect the wolves' habitats.
The work is paying off. Wolf populations have recovered from recent disease outbreaks. To make sure the wolves keep doing well, EWCP has trained people to educate local people about the wolf and how to protect it.
Thanks to the hard work of scientists and local people, the Ethiopian wolf and other Ethiopian animals face a brighter future here in Africa.
1. Different from other wolf species, Ethiopian wolves _____.| A．hunt alone |
| B．share food together |
| C．raise their babies alone |
| D．form groups in the morning |
| A．To provide food for the wolves. |
| B．To search for new wolf species. |
| C．To build more living places for wolves. |
| D．To prevent the wolves from getting diseases. |
| A．hopeless | B．helpful |
| C．interesting | D．dangerous |
4 . Horses are certainly a marvel (奇异的事物) of creation. They are extremely strong and interact (互动) with their environment through their senses. Compared to us, they see better, hear better, have a better sense of smell, and can feel the smallest insect on their bodies. They have survived by using their senses to get away from danger for centuries.
Hearing
Riding animals have excellent hearing, better than that of humans. Horses’ ears rotate (转动) 180 degrees and generally face the direction the animal is looking. They can focus one eye and ear on the rider and one eye and ear on something else. When they hear something, horses want to see the cause. Noise created by traffic, wind, and other distractions (分心的事物) can greatly affect their hearing, and cause horses to become skittish. Riding animals in more complex environments become used to disturbing noises after repeated exposure to (暴露于) them. Vehicles backfiring, gunfire, helicopters, trains and mechanical equipment can be tolerated by riding animals that are accustomed to (习惯于) them. Horses that spend time in rural areas get used to noises there, such as the sounds of farm animals or forest activities. However, all these sounds and many others can startle (使惊吓) riding animals unfamiliar with them, making it difficult for riders to keep control.
Smell
Horses have an excellent sense of smell, much better than that of humans. They may use smell to find their way back. They readily smell other animals, and they can tell differences in the smell of water. Most horses are happy to drink muddy water from a puddle (水坑) because it has a natural smell, but they may refuse to drink from an unfamiliar source. Many riders travel with an old water bucket so their horses will welcome water in the campground.
Touch
Horses are so sensitive to touch that they can feel a fly land on a single hair. Slight pressure from a rider’s legs can guide a horse forward and anything touching its body hair can alert (使警觉) the animal to trouble. If a horse brushes up against a narrow passage and feels trapped, its survival nature kicks in. Sharp objects easily cut or damage the relatively tender skin of a horse and painful or sharp impacts cause a horse to run away from the offending object, potentially injuring itself or others.
Curiosity
Some horses are exceptionally daring. Their curiosity leads them to explore anything new in their environment. They smell, push, move, pick up, or play with new objects within their reach. They may pull things into a corral (畜栏) with their teeth or kneel to reach underneath fences for something they want. Depending on the design of the fence or barrier and the size of the animal, horses may be able to reach 6 feet beyond its edge.
1. The underlined word “skittish” in Paragraph 2 probably means “_____”.| A．frightened | B．puzzled |
| C．curious | D．calm |
| A．their horses prefer to drink from a puddle |
| B．there isn’t enough water in the campground |
| C．their horses need a familiar smell to find their way back |
| D．water with a familiar smell is welcomed by their horses |
| A．They focus their eyes on the thing. |
| B．They use their feet to touch the thing. |
| C．They try their best to reach the thing. |
| D．They struggle to get out of their fences. |
| A．A brief introduction to horses’ senses |
| B．How horses use their hearing and smell |
| C．Why horses are called a marvel of creation |
| D．Comparison between horses’ senses and humans’ |
5 . The United States is one of the greatest fruit-growing countries in the world. Fine red apples come from Washington and New York. Golden oranges come from Southern California and Florida. Fruit grows in all parts of America. The kind of fruit that is grown depends on the weather in each place.
Orange trees cannot be grown where temperatures drop below freezing. Southern California and Florida are far from each other, but their weather is much the same. They do not often have freezing temperatures.
In Washington, apple trees are planted near the Atlantic Ocean. In New York, they grow near the Great Lakes. Apple trees are often planted near water. Water temperature changes more slowly than land temperature. Near water, temperature does not drop so fast. There is less chance of frost（霜冻）in late spring or early autumn. Frost can kill apples.
America has many kinds of weather. It has many kinds of soil. Because of this, they grow and eat more fruit than any other country in the world.
1. Near water, the temperature ___________.| A．changes faster | B．changes slower |
| C．doesn’t change at all | D．never changes |
| A．most fruits grow anywhere in the United States |
| B．freezing temperature are good for fruit |
| C．the same fruit can be grown in different places |
| D．fruits can only be grown near water |
| A．in the place where the temperature doesn’t drop too fast |
| B．everywhere in the USA |
| C．in Southern California and Florida |
| D．in the place where the temperature is below freezing. |
| A．orange trees usually grow where it is cold |
| B．different fruits grow in different weather |
| C．the cold cannot kill oranges and apples |
| D．apple trees cannot live through cold winter |
| A．The fruit we eat comes from many places in the country. |
| B．Orange trees are often planted near water. |
| C．The soil is about the same in all the states of the country. |
| D．The Americans like eating oranges and apples better than any other fruit. |
It’s very difficult for the scientists to reach an agreement because different results can be got from the same fossils. Many fossils of the same kind of dinosaurs have been dug out from one place. They might have formed when an entire group of dinosaurs got stuck (陷入) all at once, or they might have been the result of dinosaurs getting stuck one after another over a course of a few centuries. Thus we can say that dinosaurs might have in the first case lived in big groups and in the second lived alone.
Though there are two different results, dinosaur scientists now generally agree that at least some kinds of dinosaurs lived in big groups. “That’s pretty much settled at this point,” says Paul Sereno. A kind of dinosaurs called Sauropods left behind tracks in the western United States that appear to run north and south, suggesting that they even moved long distances together.
As to whether dinosaurs cared for their young, dinosaur scientists have turned to the closest living relatives of dinosaurs-birds and crocodiles-for possible models. Birds give a lot of care to their young, while crocodiles just help their young to the water. The discovered fossils of dinosaurs sitting on their eggs and staying with their young suggest the parents were taking care of their babies, but we still cannot say that all dinosaurs did the same.
There is still a long way to go before the above questions could be answered. Dinosaur scientists, will have to find more proof to reach an agreement.
1. Dinosaur scientists can get information directly by .
| A．studying dinosaur fossils |
| B．examining modern animals |
| C．watching dinosaurs |
| D．using telescopes |
| A．Half of the dinosaurs lived alone. |
| B．Most dinosaurs moved long distances. |
| C．Many dinosaurs settled in the north. |
| D．Some dinosaurs lived in big groups. |
| A．watching many kinds of animals |
| B．studying dinosaurs’ living relatives |
| C．following the tracks left behind |
| D．working on dug-out dinosaur eggs |
| A．Birds hardly pay attention to their young. |
| B．Baby crocodiles can look after themselves well. |
| C．Some dinosaurs took care of their young. |
| D．Birds and crocodiles take good care of their young. |
