题目内容
（请给出正确答案）
When sharks quickly move their tail, they probably become ______.
A．offensive
B．indifferent
C．interested
D．friendly
如果结果不匹配，请 联系老师 获取答案
更多“When sharks quickly move their…”相关的问题
When sharks quickly move their tail, they probably become ______.
A．friendly
B．interested
C．indifferent
D．offensive
根据以下材料，回答题
Sharks Perform. a Service for Earth"s Waters
It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to 51______ people frequently. But these fish perform. a 52______ service for earth"s waters and for human beings. Yet business and sport fishing are threatening their 53______ Some sharks are at risk of disappearing from 54______
Warm weather may influence both fish and shark activity. Many fish swim near coastal areas 55______ their warm waters. Experts say sharks may follow the fish into the same areas，56______ people also swim. In fact， most sharks do not purposely charge at or bite humans. They are thought to mistake a person 57______ a sea animal， such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the 58______ when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack.
A shark has an extremely good sense of smell4. It can find small amounts of substances in water， such as blood， body liquids and 59______ produced by animals. These powerful 60______ help sharks find their food. Sharks eat fish， any 61______ sharks， and plants that live in the ocean.
Medical researchers want to learn more about the shark"s body defense， and immune 62______ against disease. Researchers know that sharks 63______ quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the world"s 64______. They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too 65______
This protects the plants and other forms of life that exist in the oceans.
回答（51）题 查看材料
A.attack
B.meet
C.love
D.visit
Sharks Perform. a Service for Earth's Waters
It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to 【51】______ people frequently. Although these fish perform. a valuable 【52】______ for earth's waters and for human beings, business and sport fishing are threatening their 【53】______. As a result, some sharks are at risk of disappearing from Earth.
Warm weather may influence both fish and shark 【54】______. Many fish swim near coastal areas because of their 【55】______ waters. Experts say sharks may follow the fish into the same areas, 【56】______ people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person 【57】______ a sea animal, such as a seal(海豹) or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up, because those are the times when sharks are looking for 【58】______. Experts also say that bright colors and shiny jewelry(珠宝) may cause sharks to attack.
A shark has an extremely good sense of 【59】______, with which it can find small amounts of substances in water, such as blood, body liquids and chemicals 【60】______ by animals. These powerful senses help sharks find their food. Sharks eat fish, any 【61】______ sharks, and plants that live in the ocean.
Medical researchers want to learn more about the shark's body defense and immune(免疫的) 【62】______ against disease. Researchers know that sharks 【63】______ quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the world's oceans, as they eat injured and diseased fish. Their 【64】______ activities mean that the numbers of other fish in ocean waters do not become too 【65】______. This protects the plants and other forms of life that exist in the oceans.
A．attack
B．meet
C．recognize
D．visit
根据材料，回答题。
Sharks Perform. a Service for Earth"s Waters.
It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to________ （51 ）people frequently. But these fish perform. a ________ （52 ）service for earth"s waters and for human beings. Yet business and sport fishing are threatening their________ （53）. Some sharks are at ________ （54） of disappearing from earth.
Warm weather may influence both fish and shark activity. Many fish swim near coastal areas________ （55 ） their warm waters. Experts say sharks may follow the fish into the same areas，________ （56）people also swim. In fact，most sharks do not purposely charge at or bite humans.
They are thought to mistake a person________ （57 ） a sea animal， such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up. Those are the________.（58 ）when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack.
A shark has an extremely good sense of smell. It can find small amounts of substances in water， such as blood， body liquids and ________ （59）produced by animals. These powerful________ （60） help sharks find their food. Sharks eat fish， any________ （61 ） sharks ，and plants that live in the ocean.
Medical researchers want to learn more about the shark"s body defense and immune systems________ .（62） disease. Researchers know that sharks ________ （63）quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the world"s________.（64）. They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too________ （65）. This protects the plants and other forms of life that exist in the oceans.
回答（51）题 查看材料
A.attack
B.meet
C.love
D.visit
下面的短文有15处空白，请根据短文内容为每处空白确定一个最佳选项。
Sharks Perform. a Service for Earth's Waters
It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to (51) people frequently. Although these fish perform. a valuable (52) for earth's waters and for human beings, business and sport fishing are threatening their (53) . As a result, some sharks are at risk of disappearing from Earth.
Warm weather may influence both fish and shark (54) . Many fish swim near coastal areas because of their (55) waters. Experts say sharks may follow the fish into the same areas, (56) people also swim. In fact, most sharks do not purposely charge at or bite humans. They are thought to mistake a person (57) a sea animal, such as a seal (海豹) or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up, because those are the times when sharks are looking for (58) . Experts also say that bright colors and shiny jewelry (珠宝) may cause sharks to attack.
A shark has an extremely 'good sense of (59) , with which it can find small amounts of substances in water, such as blood, body liquids and chemicals (60) by animals. These powerful senses help sharks find their food. Sharks eat fish, any (61) sharks, and plants that live in the ocean.
Medical researchers want to learn more about the shark's body defense and immune (免疫的) (62) against disease. Researchers know that sharks (63) quickly from injuries. They study the shark in hopes of finding a way to fight human disease.
Sharks are important for the world's oceans, as they eat injured and diseased fish. Their (64) activities mean that the numbers of other fish in ocean waters do not become too (65) . This protects the plants and other forms of life that exist in the oceans.
51 A meet B attack C recognize D visit
Animals on the Move
It looked like a scene from “Jaws” but without the dramatic music. A huge shark was lowly swimming through the water, its tail swinging back and forth like the pendulum of a clock.
Suddenly sensitive nerve ending in the sharks skin picked up vibrations of a struggling fish. The shark was immediately transformed into a deadly, efficient machine of death. With muscles taut, the shark knifed through the water at a rapid speed. In a flash the shark caught its victim, a large fish, in its powerful jaws. Then, jerking its head back and forth, the shark tore huge chunks of flesh from its victim and swallowed them. Soon the action was over.
Moving to Survive
In pursuing its prey, the shark demonstrated in a dramatic way the important role of movement, or locomotion, in animals.
Like the shark, most animals use movement to find food. They also use locomotion to escape enemies, find a mate, and explore new territories. The methods of locomotion include crawling, hopping, slithering, flying, swimming, or walking.
Humans have the added advantage of using their various inventions to move about in just about any kind of environment. Automobiles, rockets, and submarines transport humans from deep oceans to as far away as the moon. However, for other animals movement came about naturally through millions of years of evolution. One of the most successful examples of animal locomotion is that of the shark. Its ability to quickly zero in on its prey has always impressed scientists. But it took a detailed study by Duke University marine biologists S. A． Wainwright, F． Vosburgh, and J. H. Hebrank to find out how the sharks did it. In their study the scientists observed sharks swimming in a tank at Marine land in Saint Augustine, Fla. Movies were taken of the sharks’ movements and analyzed. Studies were also made of shark skin and muscle.
Skin Is the Key
The biologists discovered that the skin of the shark is the key to the animal’s high efficiency in swimming through the water. The skin contains many fibers that crisscross like the inside of a belted radial tire. The fibers are called collagen fibers. These fibers can either store or release large amounts of energy depending on whether the fibers are relaxed or taut. When the fibers are stretched, energy is stored in them the way energy is stored in the string of a bow when pulled tight. When the energy is released, the fibers become relaxed.
The Duke University biologists have found that the greatest stretching occurs where the shark bends its body while swimming. During the body’s back and forth motion, fibers along the outside part of the bending body stretch greatly. Much potential energy is stored in the fibers. This energy is released when the shark’s body snaps back the other way.
As energy is alternately stored and released on both sides of the animal’s body, the tail whips strongly back and forth. This whip-like action propels the animal through the water like a living bullet.
Source of Energy
What causes the fibers to store so much energy？ In finding the answer the Duke University scientists learned that the sharks similarity to a belted radial tire doesnt stop with the skin. Just as a radial tire is inflated by pressure, so, too, is the area just under the sharks collagen “radials”. Instead of air pressure, however, the pressure in the shark may be due to the force of the blood pressing on the collagen fibers.
When the shark swims slowly, the pressure on the fibers is relatively low. The fibers are more relaxed, and the shark is able to bend its body at sharp angles. The animal swims this way when looking around for food or just swimming. However, when the shark detects an important food source, some fantastic involuntary changes take place.
The pressure inside the animal may increase by 10 times. This pressure change greatly stretches the fib
A．to find food
B．to avoid being chased by its enemies
C．to find a new place to live
D．to show its braveness
By the second sentence of Paragraph 2, the author means to show that ______.
A．pigs attack human beings more frequently than sharks
B．people get hurt much more easily in a car accident
C．people get killed more easily by pigs or car accident than by sharks
D．sharks rarely kill human beings when they are not provoked to do so
It's a classic mystery of the deep. Why does the hammerhead shark (双髻鲨)have the bizarrely shaped head from which it gets its name？
There have been a variety of suggested explanations. Some simply say that the sharks use their heads to "hammer" and pin down their favourite food. More plausibly, others have speculated that the wide lobes(圆形突出部分)of the hammerhead allow it to have longer electrorecep-tots, the organs that all sharks use to detect the electric fields produced by nearby prey. This might allow hammerheads to sense subtler electric fields from more distant prey than their narrow-headed cousins.
Now it turns out that the shark's head does indeed help it find and capture prey, but not in the way that zoologists expected. Stephen Kajlura and Kim Holland of the University of Hawaii at Manoa set out to test the conventional theory by tricking young sharks into chasing phantom (虚构的)prey. Using a system of wires on the bottom of a shallow pool, they set up electric fields that mimicked those created by the bottom-dwelling shrimp and fish that form. the sharks' usual diet.
Sure enough, hungry sharks abruptly turned towards an electric field when they detected it. But when the researchers measured the distance at which this happened they found it was the same for 13 young hammerheads as it was for 12 young sandbar sharks(沙堤鲨),which have normal-shaped heads.
The two types of sharks proved equally adept at sensing the electric fields: each was able to detect the source from up to 30 centimetres away. That ruled out any improved sensitivity from the wider head. However, the hammerheads enjoy another more prosaic(平淡无奇的)advantage: their wider heads let them sweep more than twice as wide a swathe of the seafloor as they swim, which must boost their chance of encountering food.
The researchers also found that hammerheads could turn more sharply when they detected the phantom prey. "They're a much more bendy shark , "says Kajlura, who is now at the University of California at Irvine. In part, that's because they have more slender bodies than the sandbar sharks. However, Kajiura has other unpublished data that suggests that the hammerheads' broad heads can act as fins to improve manoeuvrability(机动性).
So far, the researchers have only experimented with young sharks, so adult hammerheads may gain some other advantage from their head shape.
The passage is mainly about ______.
A．the different species of sharks
B．the differences between hammerhead and sandbar sharks
C．how hammerhead sharks detect their prey
D．special functions of the hammerhead sharks
SWIMMING WITH SHARKS
Oahu's Most Thrilling Adventure!
Guaranteed Sharks!
- No experience necessary
- No age limit
- All gear and equipment provided
Observe them in the open ocean from the safety of a shark cage!
A metal cage with strong Plexiglas windows gives you the closest, most exhilarating shark encounter you could ever imagine!
808-222-9393
Oahu Shark Adventure
www.oahusharkadventure.com
Brendan,
I think I found the perfect activity for Mr. Mendoza when he's visiting the Honolulu offices next month. Check out this Web site: www.oahusharkadventure.com
This might seem a little extreme, but we all know how much Mr. Mendoza loves the ocean and scuba diving. We bring him scuba diving on every trip he takes out here. But I also know that he's fascinated by sharks. The last time he was in Hawaii he was reading a book about them and would bring them up in conversation every chance he had. So I think this would be perfect for him — something different but something he would enjoy very much.
My brother-in-law went on a shark adventure through Oahu Shark Adventure when my sister and her family came to visit me last summer. He said it was very safe, very well organized, and an experience that he will never forget.
So what do you think？ Perhaps we can discuss the idea with the whole team on Thursday. We can find out if we have any volunteers to go on a shark-viewing adventure with Mr. Mendoza — if we're all in agreement that it's a good idea.
Jung-wha
What information does the advertisement provide？
A．A list of prices
B．A schedule of times
C．Recommended sites for visitors
D．Equipment and experience requirements
Vent life dies quickly when exposed to light.
A．Y
B．N
C．NG
