题目内容
（请给出正确答案）
A、the Atlantic Ocean
B、the Pacific Ocean
C、the Arctic Ocean
D、the Indian Ocean
简答题官方参考答案
（由简答题聘请的专业题库老师提供的解答）
抱歉！暂无答案，正在努力更新中……
更多“Three oceans border Canada’s shores EXCEPT ________.”相关的问题
A．had been captured
B．being always captured
C．only to be captured
D．unfortunately captured
A、Because of the economic size.
B、Because of the distance.
C、Because of political factors.
D、Because of the border effect.
A．had been captured
B．being always captured
C．only to be captured
D．unfortunately captured
Summarize advantages and disadvantages of three common methods, including DBSCAN, GMM, and k-means, in case of big data and missing data. In 2D, assume 2 clusters, each randomly generate 10 points, then implement k-means. In 2D, randomly generate 100 points, and free to select the radius and MinPts (key parameters in DBSCAN), identify each point with noise, core, or border in python, then output the density-reachable points. To do GMM estimation, we commonly introduce EM method. please infer the expectation of hidden variable Z in e-step and log-likelihood in m-step.
Part A
Directions: Read the following three texts. Answer the questions on each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1.
For millennia man has exploited and often destroyed the riches of the land. Now man covets the wealth of the oceans, which cover nearly three-quarters of the earth. But the scramble for minerals and oil, for new underwater empires, could heighten international tensions and set a new and wider stage for world conflict.
Even the most conservative estimates of sources in the seabed stagger the imagination. In the millions of miles of ocean that touch a hundred nations live four out of five living things on earth. In the seabed, minerals and oil have been proved to exist in great supply. The oceans are a source of pure water and food protein, of drugs and building materials; they are even possibly a living place for man himself and a key to survival for doubling population on the land.
Man may yet learn to use a tiny fraction of this wealth. Unless international law soon determines how it shall be shared, that fraction alone could set off a new age of colonial war. Is the deep seabed, like the high seas, common to all？ Or, like the wilderness areas of land, is it open to national claim by the use and occupation of the first or the strongest pioneer？ The question of what is to be done to regulate and control exploitation of the seabeds is no longer a theoretical matter. It is a problem of international concern. We must decide how to divide this great wealth equitably among nations. But wealth is not the only thing at stake. We must also learn how to protect the oceans from the threat of pollution.
A few years ago, "practical" men dismissed speculations about wealth in the sea. "That is economic foolishness," they said. It will never be economically profitable to exploit the seabeds, no matter how great the riches to be found there. Unfortunately, they underestimated the temptation of gold as the mother of invention.
The word "covets"(Line 1, Para1) can be replaced by ______.
A．exploits
B．damages
C．desires
D．destroys
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
If the salinity (含盐量) ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation--conversion of liquid water to water vapor. In this manner, the salinity is increased, since the salts stay behind. If this is carried to the extreme, of course, white crystals of salt would be left behind.
The opposite of evaporation is precipitation (降水), such as rain, by which water is added to the ocean. Here the ocean is being diluted (稀释) so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff (形成地表水部分的降雨).
Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly-formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, off Antarctica, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.
The best title of the passage can be _________.
A．Typical Oceans and Their Respective Features
B．The Causes of the Changes in Salinity of Ocean Water
C．Different Oceans Have Different Salinity
D．The Precipitation and Evaporation of Oceans
If the salinity(含盐量) of ocean waters is analyzed, it is found to vary only slightly from place to place.Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation--conversion of liquid water to water vapor. In this manner, the salinity is increased, since the salts staybehind. If this is carried to the extreme, of course, white crystals of salt would be left behind.
The opposite of evaporation is precipitation(降水), such as rain, by which water is added to the ocean. Here the ocean is being diluted(稀释) so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff(形成地表水部分的降水).
Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions whererivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, off Antarctica, the densest water in the oceans is formed as a result of this freezingprocess, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the oceans of the world.
Choose correct answers to the question: The best title of the passage can be “_____”.
A.Typical Oceans and Their Respective Features
B.The Causes of the Changes in Salinity of Ocean Water
C.Different Oceans Have Different Salinity
D.The Precipitation and Evaporation of Oceans
Which of the following processes will increase salinity of ocean waters？A.Evaporation.
B.Precipitation.
C.Melting.
D.Dilution.
According to this passage, the sea _ is likely to have the lowest salinity.A.in tropical areas
B.off Antarctica
C.of high rainfall
D.with abundant
The Weddell Sea _____.
A.is a good example of increased salinity in freezing sea water
B.is much larger in area than the Arctic oceans
C.has a much lower salinity now than ever
D.has the denser water in its upper parts
Coastal regions are mentioned as cases where _____.A.sea water is less salty because fresh water joins in
B.rivers carry industrial exhaust into sea
C.sea ice tends to melt more quickly than in the center of oceans
D.heavy water sinks to the deeper portions of the oceans
Section B
Directions: There are 2 passages in this section. Each passage is followed by some questions or unfinished statements. For each of them there are four choices marked A, B, C and D. You should decide on the best choice.
If the salinity(含盐量)of ocean waters is analyzed, it is found to vary only slightly from place to place. Nevertheless, some of these small changes are important. There are three basic processes that cause a change in oceanic salinity. One of these is the subtraction of water from the ocean by means of evaporation—conversion of liquid water to water vapor. In this manner, the salinity is increased, since the salts stay behind. If this is carded to the extreme, of course, white crystals of salt would be left behind.
The opposite of evaporation is precipitation(降水), such as rain, by which water is added to the ocean. Here the ocean is being diluted(稀释)so that the salinity is decreased. This may occur in areas of high rainfall or in coastal regions where rivers flow into the ocean. Thus salinity may be increased by the subtraction of water by evaporation, or decreased by the addition of fresh water by precipitation or runoff(形成地表水部分的降雨).
Normally, in tropical regions where the sun is very strong, the ocean salinity is somewhat higher than it is in other parts of the world where there is not as much evaporation. Similarly, in coastal regions where rivers dilute the sea, salinity is somewhat lower than in other oceanic areas.
A third process by which salinity may be altered is associated with the formation and melting of sea ice. When seawater is frozen, the dissolved materials are left behind. In this manner, seawater directly beneath freshly-formed sea ice has a higher salinity than it did before the ice appeared. Of course, when this ice melts, it will tend to decrease the salinity of the surrounding water.
In the Weddell Sea, off Antarctica, the densest water in the oceans is formed as a result of this freezing process, which increases the salinity of cold water. This heavy water sinks and is found in the deeper portions of the-oceans of the world.
The best title of the passage can be"______"
A．Typical Oceans and Their Respective Features
B．The Causes of the Changes in Salinity of Ocean Water
C．Different Oceans Have Different Salinity
D．The Precipitation and Evaporation of Oceans
根据下列文章,请回答 16～22 题。
Where Has the Salt Come from？
Every now and then, we meet a fact about our earth that makes us feel strange and no answer for the fact has yet been found. Such a fact is the existence of salt in the oceans. How did it get there？
We simply do not know how the salt got into the ocean! We do know, of course, that salt is water-soluble, and so passes into the oceans with rainwater. The salt of the earth's surface is constantly being dissolved (溶解) and is passing into the ocean.
But we do not know whether this can explain the huge quantity of salt in oceans, tf ait the oceans were dried up, enough salt would be left to build a wall 180 miles high arid a mile thick. Such a wall would reach once around the world at the Equator (赤道)!
The common salt that we all use is produced from seawater or the water of salt lakes, from salt springs (源泉) and from deposits of rock salt. The concentration (浓度) of salt in seawater ranges from about three per cent to three-and-one-half percent. The Dead Sea, which covers an area of about 340 square miles, contains about 11,600,000,000 tons of salt!
On the average, a gallon (加仑) of seawater contains about a quarter of a pound of salt. The beds of rock salt that are found in various parts of the world were all originally formed by the evaporation (蒸发) of seawater millions of years ago. It is believed that the thick rock-salt deposits were formed after about nine-tenth of the volume of seawater had been evaporated.
Most commercial salt is obtained from rock salt. The usual method is to drill wells (井) down to the salt beds. Pure "water is pumped down (抽进去) through a pipe. The water dissolves the salt and it is forced through another pipe up to the surface.
第 16 题 We have not fully understood how salt got into the ocean.
A．Right
B．Wrong
C．Not mentioned
Passage Three
Did you know that a turtle can lay twelve eggs in one minute？ A large sea turtle lays around 150 eggs at a time. She lays all these eggs in just a few minutes.
Large sea turtles live in the warm seas of the world. Except for when they lay their eggs, they spend their whole lives in water. When it is time to lay their eggs, the females swim to land. They usually return to the place where they themselves were born. How they find their way back there is a mystery.
When they reach shore, the big, heavy turtles crawl slowly up to the high water mark. Using their flippers, they pull themselves along the sand. They struggle like mountain climbers to attain their goal. When they finally reach dry sand, they rest before beginning the difficult task of laying eggs.
The turtles lay the eggs in deep holes and cover them with warm sand. The sand protects the eggs from harm. Then the females leave them. After a few weeks, if you happened to be walking along the beach, you might see the sand begin to shake in one spot. Then you would see tidy black balls coming out of the sand. The tidy heads of baby turtles!
Baby turtles have a build-in sense of direction. As soon as they are hatched, they head for the water. Once the babies swim out to sea, they don't touch shore again until it is time for them to lay their own eggs.
41. The first sentence lets us know that this passage is about ______.
A. turtles
B. oceans
C. time
D. eggs
警告：系统检测到您的账号存在安全风险
为了保护您的账号安全，请在“简答题”公众号进行验证，点击“官网服务”-“账号验证”后输入验证码“”完成验证，验证成功后方可继续查看答案！
