1. Which season is it now?
A.Summer. | B.Fall. | C.Winter. |
A.The northeast coast. | B.The northwest coast. | C.The southwest coast. |
A.Rain. | B.Snow | C.Wind. |
A.In the west of Ireland. |
B.In the north of Scotland. |
C.In the south of America. |
A.Sunny. | B.Windy. | C.Rainy. |
3 . Endangered polar bears are breeding (繁殖) with grizzly bears (灰熊), creating “pizzaly” bears (灰北极熊), which is being driven by climate change, scientists say.
As the world warms and Arctic sea ice thins, starving (饥饿的) polar bears are being forced ever further south to relieve (减轻) hunger, where they meet grizzlies, whose ranges (范围) 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 (减少) 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 (超越) them, but also to polar bears’ highly specialized diets.
“Polar bears mainly consumed (消耗) 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 (可替代的) food sources, like seabird eggs, it could be a tipping point fo r 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 (生物多样性) 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, ‘pizzaly’ 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 (选择). |
C.Climate preference. |
D.Improved breeding ability. |
A.Because “pizzly” bears take up polar bears’ ranges. |
B.Because polar bears cannot find enough food. |
C.Because “pizzly” bears take up polar bears’ food. |
D.Because the ice melts so fast. |
A.A rare chance. | B.A critical stage (关键阶段). |
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. |
1. What has the weather been like recently?
A.Cloudy. | B.Rainy. | C.Sunny. |
A.Buying a new phone. | B.Taking an umbrella. | C.Traveling by car. |
1. What will the weather be like later today?
A.Rainy. | B.Cloudy. | C.Windy. |
A.10°C. | B.18°C. | C.28°C. |
A.Take an umbrella. | B.Follow the forecast. | C.Put on more clothes. |
A.Rainy. | B.Sunny. | C.Snowy. |
A.Windy. | B.Rainy. | C.Cloudy. |
8 . In June a massive “heat dome” baked the famously temperate Pacific Northwest, subjecting parts of Washington State, Oregon and western Canada to extreme temperatures. It is virtually impossible that heat waves like this would have occurred without climate change. Scientists estimate it was a one-in-1,000-year event. “And that’s an ‘at least,’ ” says Kristie. L. Ebi. “It could be more rare than that.” If warming reaches two degrees Cabove preindustrial levels — the threshold (阈值) that most national governments have agreed to try to avoid in hopes of reducing climate change impacts, “that event could occur every five to 10 years,” Ebi says.
“In an average year in the U.S., heat kills more people than any other type of extreme weather,” says Kristina Dahl, a climate scientist. Hundreds of people died in the recent Pacific Northwest heat wave, according to estimates: there were at least 486 deaths in British Columbia, 116 in Oregon and 78 in Washington. A recent U.S. Centers for Disease Control and Prevention report found there were more than 3,500 emergency department visits for heat-related illness this past May and June in a region that includes Oregon and Washington State.
The human body functions best at 98.6 degrees F (37 degrees C). The body has mechanisms to rid itself of excess heat, most notably sweating. But at a certain point, that fails to work, causing loss of consciousness. People can eventually acclimatize to some level of heat. If you live in a hot climate or work in hot conditions for a period of weeks or months, your body becomes more efficient at sweating and cooling itself down. This process takes time, however.
As the planet warms, heat waves like these this year are becoming frighteningly common and catching climate scientists off guard. “Even a lot of our climate models that project out how frequent extreme heat will be in the future wouldn’t have necessarily predicted this level of heat for that part of the country,” Kristina Dahl says. “But then to realize that I am seeing it in my lifetime, and living it right now, is really terrifying.”
1. What does Ebi’s saying imply in Paragraph 1?A.Heat dome has affected at least three regions. |
B.Temperature reaches the threshold immediately. |
C.Heat waves affect the Pacific Northwest greatly. |
D.Severe weather could become frighteningly common. |
A.Many areas are badly affected by heat waves. |
B.Heat waves pose a major risk to public health. |
C.More people died of illnesses in this summer. |
D.Latest news on heat waves are widely reported. |
A.Adapt. | B.Settle. | C.Respond. | D.Object. |
A.ruins his normal daily life. |
B.gets scientists prepared to it. |
C.fails to be accurately forecast. |
D.should be examined frequently. |
9 . Amphibians are animals that can live both on land and in water. A new global assessment has found that 41% of amphibian species that scientists have studied are threatened with extinction. That’s up from 39% reported in the last assessment in 2004.
The study, published on Wednesday in the journal Nature, found that the loss of habitat from the legal and illegal expansion of farming and ranching (放牧) contributes most to the extinction risk of amphibians worldwide. But a growing percentage of amphibian species are now also pushed to the edge of extinction by novel diseases and climate change, the study found.
Amphibians have distinct life stages that each often require separate habitats, so they can be disturbed by changes in either water or land environments, said University of Texas biologist Michael Ryan, who was not involved in the study. They are also at risk because of their delicate skin. Most amphibians absorb oxygen to breathe through their skin, and so they do not have scales (鳞), feathers or fur to protect them. Chemical pollution, bacteria and fungal (真菌的) infections impact them quickly, as do heightened swings in temperature and dampness levels due to climate change.
For example, frogs are active usually at night. If it’s too hot, they won’t come out even at night because they would lose too much water through their skin, said co-author and researcher Patricia Burrowes. But remaining in sheltered resting places limits frogs’ ability to eat and to produce.
Juan Manuel Guayasamin, a frog biologist at the University San Francisco of Quito, Ecuador, said that advances in technology to track animals and climate variations allowed the new study to use much more precise data than the 2004 assessment. “We have a much better understanding of some risks,” said Guayasamin.
The study identified the greatest concentrations of threatened amphibian species in several biodiversity hot spots, including the Caribbean islands, the tropical Andes, Madagascar and Sri Lanka. Other locations with large numbers of threatened amphibians include Brazil’s Atlantic Forest, southern China and the southeastern United States.
1. What has the new study found?A.Amphibian populations are now extinct. |
B.The number of amphibians is rising slightly. |
C.The extinction risk of amphibians has declined. |
D.More amphibian species are endangered than before. |
A.Habitat loss. | B.Illegal hunting. | C.Novel diseases. | D.Climate change. |
A.The unusual living habits of frogs. | B.The unique features of the frog skin. |
C.The effect of climate change on amphibians. | D.The urgency of protecting amphibians’ habitats. |
A.Its methods are debatable. | B.Its findings are more reliable. |
C.It needs to be better organized. | D.It covers wide geographical areas. |
A.Cool. | B.Warm. | C.Cold. |