The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ___ 9-story building.
A. the; the B. a; a C. the; a D. a; the
高三英语单项填空困难题
The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ___ 9-story building.
A. the; the B. a; a C. a; the D. the; a
高三英语选择题简单题查看答案及解析
The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ___ 9-story building.
A. the; the B. a; a C. a; the D. the; a
高三英语单项填空中等难度题查看答案及解析
The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ___ 9-story building.
A. the; the B. a; a C. the; a D. a; the
高三英语单项填空困难题查看答案及解析
The biggest whale is ___ blue whale, which grows to be about 29 meters long—the height of ___ 9-story building.
A. the; the B. a; a C. a; the D. the; a
高三英语单项填空中等难度题查看答案及解析
The biggest whale is _____ blue whale, which grows to be about 29 meters long—the height of ____ 9-story building.
A. the; the B. a; a C. a; the D. the; a
高三英语单项填空简单题查看答案及解析
The biggest whale is ________ blue whale，which grows to be about 29 meters long—the height of ________ 9story building.
A．the；the B．a；a C．a；the D．the；a
高三英语单项填空中等难度题查看答案及解析
The biggest whale is ________ blue whale，which grows to be about 29 meters long—the height of ________ 9story building.
A．the；the B．a；a C．a；the D．the；a
高三英语单项填空中等难度题查看答案及解析
The biggest whale is ________ blue whale，which grows to be about 29 meters long—the height of ________ 9－story building.
A．the；the B．a；a C．a；the D．the；a
高三英语单项填空中等难度题查看答案及解析
Imagine trying to test the memory of the blue whale—the biggest animal that exists or has ever existed, a 190-ton behemoth that dwarfs (使相形见绌) even the largest dinosaur, a leviathan that is rarely seen except when it comes up for air. How would you subject such a creature to a psychological test?
You can’t, exactly. But there is another way to get a sense of how their minds work. For years, scientists have been fitting radio tags to these giants to track their whereabouts (下落). By analyzing a decade’s worth of that data, Briana Abrahms from the National Oceanic and Atmospheric Administration has shown that these animals fine-tune the paths of their migrations to track the historical abundances of krill—the tiny crustaceans that they eat. Rather than finding where their prey (捕获物) currently is, they go after the places where their prey was in years past. Their migrations, in other words, are guided by memory. So what happens in a world where memory might lead them away from the right path?
Countless species of animals migrate over long distances to exploit far-flung sources of food, but these voyages aren’t just about getting to the final destination. The journey itself can be a sort of food tour, too. Migrating animals often adjust the pace and timing of their movements to hit pulses of seasonal food that spring up along their path. The ecologist Sandra van der Graaf described this as “surfing the green wave” after first observing it among barnacle geese. Others have found the same pattern among wasps, elk, mule deer, and brown bears.”
The blue whales of the North Pacific spend their winters in their breeding grounds off California and Costa Rica. Come spring, they swim up the coast of North America toward the food-rich summer waters of the Pacific Northwest. They could make the journey in two months (and they do, on the reverse trip back south). Instead, they take twice that time, pausing to gorge (狼吞虎咽) themselves on blooms of krill that appear along the way. It’s a leisurely season-long tour of a continent-wide buffet line.
Scientists can get a good sense of this changing buffet by measuring the concentrations of chlorophyll in different patches of ocean. This green pigment (色素) reflects the amount of plankton, which in turn is eaten by krill. The more chlorophyll there is, the more food a blue whale might find.
By comparing chlorophyll counts to whale movements, Abrahms and her team expected to see that “they follow the timing of their prey, as it becomes available,” she says. But they were surprised to learn that the animals very rarely tracked contemporary waves of krill. Instead, their movements were strongly correlated (相关联) with 10-year historical averages of chlorophyll. Put it this way: You could predict a blue whale’s movements with far more accuracy by looking at where their food has been than where their food currently is.
1.How are the scientists carrying out a psychological test on the blue whales?
A. They wait for the blue whales to approach the sea surface.
B. They induce the blue whales to accept the memory test.
C. They count on a tracking technique to accumulate data.
D. They compare the blue whales with the large dinosaurs.
2.What might migrating animals do if they are misguided by memory?
A. They might try their best to get to the final destination.
B. They might fall back on the seasonal food along the way.
C. They might accelerate the pace to cover longer distances.
D. They might surf the ocean wave to save time and energy.
3.What does the continent-wide buffet line in Paragraph 4 indicate?
A. The breeding grounds of the blue whales are lacking in food.
B. Chlorophyll can be defined as the beginning of the food chain.
C. Contemporary waves of krill can reflect whale movements.
D. The season change determines the hunting route of the whales.
高三英语阅读理解困难题查看答案及解析
Blue whales are the largest animals ever known to have existed on the planet, and they can grow to a length of 100 feet and weigh more than 330,000 pounds. But recently researchers have found that these whales are on the move and they have migrated from California waters to areas off Canada and Alaska for the first time since commercial whaling ended in 1965.
The researchers identified 15 blue whales that have appeared off the coast of British Columbia and the Gulf of Alaska since 1997. Four of these whales were recognized as ones that were once sighted off California shores, suggesting that the whales are returning to an old migration pattern between the coasts.
Before commercial whaling began in the early 1900s, blue whales were found widely throughout the North Pacific and California waters. But from the 1920s to the 1960s,whaling severely reduced the whale populations. Blue whales never recovered in the Northern Pacific, making sightings in this area rare. However, much larger groups of whales have been observed close to California since the 1970s.
The scientists had previously thought that the California population was separate from the population that had historically lived in North Pacific waters. But the current study shows that whales off the coast of British Columbia and the Gulf of Alaska are likely part of the California population.
To identify the blue whales, the researchers looked at photos of cetaceans taken in the North Pacific Ocean and compared them with a library of blue whale pictures taken along the West Cost of the United States and Southern Pacific. Up to now, the researchers are not quite sure why the whales are changing their migration patterns, but they suspect that the whales may be following their food moving farther north by the changes in ocean conditions.
1.According to the passage, blue whales are .
A. following a fixed route of migration
B. dying out due to commercial whaling
C. moving from the south to the north
D. rarely found in the Southern Pacific
2.The whale population in the northern Pacific .
A. is different from the California population
B. is probably part of the California population
C. has become the largest group since the 1970s
D. has lived there since the 1960s
3.The underlined word "cetaceans" in Paragraph 5 probably means .
A. land creatures B. whale species
C. ocean conditions D. migration patterns
4.What might make blue whales migrate according to the researchers?
A. Commercial whaling. B. Weather conditions.
C. Life reproduction. D. Food resources.
高三英语阅读理解中等难度题查看答案及解析