Steller or Northern Sea Lions are sometimes confused with California Sea Lions but are much larger and lighter in color. Males may grow to 11 feet in length and weigh almost 2,500 pounds.
Stellers are not often seen in bays or rivers. Steller pups are born on offshore islands from mid-May to mid-July and weigh 35—50 pounds.
The current population of Steller Sea Lions is about 40,000 along the entire Pacific coast. There is great concern about this species. The western Aleutian stock has dropped by 80 percent in the last 30 years. In 1997, the western stock in Alaska was listed as endangered.
| A．Steller Sea Lions eat a variety of fishes. |
| B．Reasons for this decline are not known. |
| C．The male has a thick neck and looks like a lion. |
| D．They spend about half their time on land and half in water. |
| E．Mothers stay with pups for one to two weeks before hunting at sea. |
| F．They forbid the killing, harming or disturbance of any sea mammal. |
| G．Females are much smaller, growing to 9 feet in length and weighing up to 1,000 pounds. |
相似题推荐
【推荐1】Plant-eating dinosaurs probably arrived in the northern half of the world millions of years after meat-eating dinosaurs, a recent study found. Their late arrival was likely a result of climate changes that took place hundreds of millions of years ago.
The study used a new way to ascertain the age of dinosaur remains found in Greenland. Researchers found that the plant-eating dinosaurs were about 215 million years old. The mineralized（石化的）remains of bones are called fossils. Earlier, those fossils were thought to be as old as 228 million years. The findings could change how scientists think about dinosaur movements, or migrations.
The earliest dinosaurs all seemed to first develop about 230 million years ago or longer. They appeared in what is now South America. Then, the creatures moved north and spread all over the world. The new study suggests not all dinosaurs moved at the same time.
So far, scientists have not found any evidence of plant-eating dinosaurs living in the Northern Hemisphere before 215 million years ago. One of the best examples of these is the Plateosaurus, a two-legged, 7-meter-long plant-eater that weighed around 4,000 kilograms. However, meat. eaters lived worldwide by at least 220 million years ago.
During the Triassic（三叠纪）period, 230 million years ago, CO2 levels were 10 times higher than now. The Earth was hotter with no ice sheets at the poles and two areas of extreme deserts north and south of the equator（赤道）. It was so dry in those areas that there were not enough plants for the plant-eaters to survive. But there were enough insects so that meat-eaters could.
About 215 million years ago, CO2 levels dropped. The drop resulted in more plant life in the deserts. The plant-eaters were then able to make the trip. Triassic changes in CO2 levels were from volcanoes and other natural forces. The changes were different from those in our times, when the burning of coal, oil and natural gas are considered the main causes of climate change.
1. Which can best replace the underlined word "ascertain" in paragraph 2?| A．Stress. | B．Choose. | C．Make use of. | D．Find out. |
| A．It was the largest living thing at that time. | B．It was a plant-eating dinosaur. |
| C．It lived at least 220 million years ago. | D．It was the earliest dinosaur in the south. |
| A．They had enough food. | B．They had a strong body. |
| C．CO2 is harmless to them. | D．They were not afraid of dry climates. |
| A．The spread of small plants. | B．Migration of dinosaurs. |
| C．The change of the atmosphere. | D．An increase in rainfall. |
【推荐2】Searching for a new cat to add to your family? If your home already has a cat, you may wonder how your cat will welcome a new partner.
Your existing cat’s needs come first.
Shower your existing cat with extra attention. Cats can be territorial when it comes to their space; the same can be true for their owners as well.
Introduce the new cat slowly. Your cats will have the chance to get used to each other’s smell through the door. When they seem interested in meeting, you can bring one into the other’s territory.
| A．Separate the cats initially. |
| B．Make sure your cat feels at home. |
| C．Do this at least a few days after the new cat arrives. |
| D．Think about your existing cat’s personality and habits. |
| E．Your cat can get envious of a newcomer easily if feeling ignored. |
| F．Give both cats a special treat when they first meet to encourage peace. |
| G．There is a process to make the change less stressful for both you and the cats. |
【推荐3】Many early domestic (驯养的) dogs ate almost no meat. Dogs living around 3000 years ago in what is now Spain were instead fed cereals, such as millet (小米), by their owners.
Although the diet may reflect the fact that meat was relatively in lack among human societies at the time, feeding dogs with cereals could have been advantageous, says Silvia Albizuri at the University of Barcelona in Spain. It may have been a way to ensure the dogs had plenty of energy for the hard work of herding and guarding livestock (牧群), she says, particularly since these dogs “were not pets as we think of them nowadays”. Albizuri and her colleagues studied the remains of 36 dogs from Can Roqueta, an archaeological site near Barcelona. It lies on a plain near the coast and was inhabited from the Stone Age onwards. The dogs lived in the Bronze Age and Iron Age, between 1300 and 550 BC, and had been buried in pits. The researchers obtained protein from the dogs’ bones and focused on the carbon in the samples, which give an indication of what the animals ate.
The dogs’ diets differed considerably. While nine of them ate plenty of meat and 10 were omnivorous (杂食的), the rest ate mostly plants.
The finding adds to the evidence that many early domestic dogs ate little meat, says Albizuri. This trend is thought to have begun with the start of farming. “When human societies began to domesticate plants during the Neolithic period, hunting decreased and the human diet was based mainly on vegetables,” she says. “Dogs began to be fed on plants, mainly cereals.”
1. What can we know from the second paragraph?| A．The early human beings had nothing to eat. |
| B．The early dogs did not like meat at all. |
| C．There was not enough meat for early humans. |
| D．Dogs were eaten by the early human beings. |
| A．Hunters. | B．Pets. | C．Food. | D．Friends. |
| A．Bones. | B．Plants. | C．Normal dinners. | D．Meat. |
| A．Human’s habit. | B．Dog’s development. |
| C．Productive forces. | D．Social customs. |
【推荐1】At 18, Ashanthi De Silva of suburban Cleveland is a living symbol of one of the great intellectual achievements of the 20th century. Born with an extremely rare and usually fatal disorder that left her without a functioning immune system, she was treated beginning in 1990 with a revolutionary new therapy that sought to correct the defect at its very source, in the genes of her white blood cells. It worked. Although her last gene-therapy treatment was in 1992, she is completely healthy with normal immune function, according to one of the doctors who treated her, W. French Anderson of the University of Southern California. Researchers have long dreamed of treating diseases from hemophilia to cancer by replacing mutant (变异的) genes with normal ones. And the dreaming may continue for decades more. "There will be a gene-based treatment for essentially every disease, "Anderson says, "within 50 years."
It's not entirely clear why medicine has been so slow to build on Anderson's early success. The National Institutes of Health budget office estimates it will spend $432 million on gene-therapy research in 2005, and there is no shortage of promising leads. The therapeutic (有益健康的，有治疗性的) genes are usually delivered through viruses that don't cause human disease.
At the University of Pennsylvania's Abramson Cancer Center, immunologist Carl June recently treated HIV patients with a gene intended to help their cells resist the infection. At Cornell University, researchers are pursuing gene-based therapies for Parkinson's disease and a rare hereditary disorder that destroys children's brain cells. At Stanford University and the Children's Hospital of Philadelphia, researchers are trying to figure out how to help patients with hemophilia who today must inject themselves with expensive clotting drugs for life. Animal experiments have shown great promise.
But somehow, things get lost in the translation from laboratory to patient. In human trials of the hemophilia treatment, patients show a response at first, but it fades over time. And the field has still not recovered from the setback it suffered in 1999, when Jesse Gelsinger, an 18-year-old with a rare metabolic disorder, died after receiving an experimental gene therapy at the University of Pennsylvania. Some experts worry that the field will be tarnished (黯淡的) further if the next people to benefit are not patients but athletes seeking an edge. This summer, researchers at the Salk Institute said they had created a "marathon mouse" by implanting a gene that improves running ability; already, officials at the World Anti-Doping (反兴奋剂) Agency are preparing to test athletes for signs of "gene doping. "But the principle is the same, whether you're trying to help a healthy runner run faster or allow a muscular-dystrophy patient to walk. "Everybody recognizes that gene therapy is a very good idea," says Crystal. "And eventually it's going to work."
1. According to the passage, we know that ________.| A．Jesse Gelsinger give an example of modern treatment for fatal diseases |
| B．the case of Ashanthi Desilva shows the promise of gene-therapy |
| C．researchers have improved people's running ability by implanting a gene |
| D．The gene-therapy way has cured many serious diseases |
| A．greatly speeded the development of medicine |
| B．brought no immediate progress in the research of gene-therapy |
| C．realized his dream |
| D．made him a national hero |
| A．Ashanthi needs to receive gene-therapy treatment constantly. |
| B．Despite the huge funding, gene researches have shown few promises. |
| C．Therapeutic genes are carried by harmless viruses. |
| D．Gene-doping is encouraged by world agencies to help athletes get better scores. |
| A．troubled | B．pessimistic |
| C．optimistic | D．uncertain |
【推荐2】Hawks(鹰) and other raptors(猛禽) are impressive predators, and many of these species are adapted for fast, quiet flight to help them attack their prey(猎物). After all, raptors make their living by flying down to take small animals off the ground. While a hawk clearly couldn’t lift a full-grown dog, it might seem reasonable that raptors could lift a small dog, cat or possibly even a human child. Is that a reasonable concern, or just a flight of fancy?
There are urban legends about hawks stealing 12-pound pets, and some taking away kids, but these are based on wrong descriptions of how much weight these raptors can lift. Hawks and owls, for instance, can’t fly away with prey that outweighs them. And given the light weight of even big raptors like red-tailed hawks and great-horned owls —which average about 2 pounds and 3 pounds separately, — they’re unable to take away most adult dogs and cats, not to mention human children.
Some larger red-tailed hawks may be able to carry prey weighing 5 pounds,which could include not just puppies and kittens but also some adult cats and dogs from small kinds. Great-horned owls also focus on small mammals and birds, but they have the most diverse diet of any North American raptor, including larger animals like skunks, ducks and even other raptors. They don’t create a serious threat to pets overall, although they have been known to attack house cats and chickens left outside overnight.
While most pets and kids are probably safe from raptors, it still might be wise to take a few precautions, depending on the situation.
One of the most effective precautions is to watch over your pets when they’re outdoors, which is generally wise anyway, for their safety as well as that of your neighbors and local wildlife. Some pet owners try to drive raptors away, using reflective tape and so on. Some of these might work, at least for a while, but they can’t replace human supervision. If raptors fly down at your pet, an umbrella could help prevent off some species, while a flashlight can reportedly discourage owls after dark.
The presence of wild raptors suggests you live in a healthy ecosystem, and if you can bear to share space with them, there’s a good chance they’ll repay you for your tolerance. Instead of hunting pets, for example, many raptors are far more likely to hunt pests like rats.
1. What does the author think of a hawk taking away a kid?| A．It’s just imagination. |
| B．It’s a reasonable statement. |
| C．It remains to be proven. |
| D．It may happen as to big raptors. |
| A．Some big hawks can lift up to 12 pounds. |
| B．Red-tailed hawks can carry cats and dogs, large and small. |
| C．Great-horned owls prefer to eat small animals rather than large ones. |
| D．Great-horned owls in general cannot lift more than 3 pounds. |
| A．Use reflective tape. |
| B．Use a flashlight at night. |
| C．Keep an eye on your pets as much as possible. |
| D．Keep your pets under the umbrella all the time. |
| A．they can scare away harmful animals |
| B．they may help you catch rats and other pests |
| C．it helps to keep the ecosystem in balance |
| D．it helps you understand the importance of tolerance |
| A．How to protect pets from raptors. |
| B．How raptors get their food. |
| C．What prey raptors usually feed on. |
| D．Whether raptors catch pets or kids. |
【推荐3】February 13, 2022, marked the 25th anniversary (纪念日) of the Great LEGO Spill — the worst toy-related environmental disaster of all time. On this important day in 1997, the Tokio Express was hit by a huge, 28-foot high wave off the United Kingdom’s southwestern coast, tilting the ship by 60 degrees and causing it to drop 62 containers into the sea. One was filled with about 5 million colorful LEGO bricks!
Shortly after the incident, LECO pieces began washing ashore the beautiful beaches of Cornwall and Devon in southwest England. Many locals rushed to hunt for the toys. Cornwall resident Tracey Williams was among the thousands of locals that searched the beaches regularly to find the little sea-themed pieces.
In 2010 Williams moved to Cornwall and came across some LEGO pieces on her first trip to the beach. Wondering where else they had been found, she created a Facebook group. Called “Lego Lost at Sea”, it allowed her and hundreds of other collectors to share their discoveries. As it turned out, the LEGO bricks were not just washing ashore English beaches. They had also been found in Wales, Ireland, the Channel Islands, France, Belgium, and Holland, showing just how far ocean currents had carried them.
“What we’re finding now are the pieces that sank as well as the pieces that floated,” Williams says. “It’s providing us with an insight into what happens to plastic in the ocean, how far it drifts (漂移) — both on the surface of the ocean and also along the seabed—and what happens to it as it breaks down.”
No one knows when the LEGO bricks will stop appearing on the beaches. But one thing is for sure, that is, the plastic pieces will be around for centuries. A 2020 study analyzing the structure of the washed-up LEGO bricks concluded that the five million pieces could take as long as 1,300 years to degrade (降解) completely. And like all plastic products, the iconic toys will never entirely disappear. Instead, they will break down into tiny “microplastics” and be eaten by ocean animals. They will make their way up the food chain to humans.
1. What does the underlined word “tilting” in paragraph 1 probably mean?| A．Speeding up. | B．Leading something to fall. |
| C．Damaging seriously. | D．Making something not flat. |
| A．It resulted in many deaths. |
| B．It was caused by the pilot’s mistakes. |
| C．It made many LEGO bricks lost. |
| D．The ship dropped most containers. |
| A．To exchange toy blocks. | B．To collect LEGO toys. |
| C．To track the LEGO bricks. | D．To trade in toys worldwide. |
| A．They will break down completely. |
| B．They will influence human health. |
| C．They will be recovered by the maker. |
| D．They will soon disappear from the beaches. |
