2017年下半年pets5考前训练题指点
夫学须志也,才须学也。非学无以广才,非志无以成学。以下是小编为大家搜索整理的2017年下半年pets5考前训练题指点,希望对正在关注的您有所帮助!更多精彩内容请及时关注我们应届毕业生考试网!
第 1 题:Reading Comprehension(子母填空):
Secrets of Nature Still Enthral Us
Reception staff at the Natural History Museum in London were in no doubt about the message they wanted to be passed to future visitors. "Please, please tell your readers they cannot come to see the squid unless they book," pleaded one.
Over the past four days thousands have arrived to see Archie, the giant squid, after news of his unveiling -- in a tank of pickling fluid in the basement of the museums Darwin Centre -- had been revealed in newspapers and on television.
Most of the visitors were disappointed. Only a few who had booked to go on the small guided tours of the Darwin Centre, the museum's research annexe, got to see the 30ft behemoth in his new home. The rest had to do without -- and judging from the looks of museum staff, this news often went down badly.
The intensity of the public's response to Archie's arrival has been extraordinary, and reveals how deeply ingrained is our sense of wonder at the natural world, and the reverence we feel for our fellow creatures. It might be expected -- given the plethora of natural history programmes on Discovery and National Geographic channels -- that people would be bored by news of yet another zoological discovery.
But that is certainly not the case, judging by the response to the news that the most complete giant squid ever found (off the Falkland Islands) had been put on display at the Natural History Museum, and the public's recent reaction to a host of other zoological events. Examples range from the plight of the whale trapped in the Thames in January, to the millions expected to tune in to BBC1's latest David Attenborough extravaganza, Planet Earth, tonight. We are becoming ever more besotted with animals, it appears.
And it is not simply a matter of aesthetics. Some animals are cute, but Archie -- named after his formal label Architeuthis dux -- is decidedly ugly, a very long, thin, pinkish creature with collapsed eye sockets the size of dinner plates. Only a restaurateur could love Archie, you would have thought, "You could get about 600 portions of calamari out of him," admitted one particularly pragmatic member of museum staff. Nevertheless, he is gazed upon in silent awe by visitors.
"We have always been intrigued with wildlife, of course, but it is true that the public's appetite only seems to be growing," said Richard Lane, the museum's director of science. "The real irony is that, just as we are discovering more and more new species, about 15,000 a year, we are killing off other species at an equivalent rate because of habitat destruction and climate change."
There are 1.7 million species so far discovered by scientists, most of whom believe there could be up to 10million in total on Earth.
Among discoveries made in the last few weeks are a new species of rodent called Kha-Nyou (the name given to it by local people in central Laos); a marine worm called Osedax mucofloris which translates, rather beautifully, as the bone- eating snot-flower; a golden-mantled tree kangaroo, found in Indonesia's Papua province; Berlepsch's six-wired bird of paradise, known to the Victorians but a mystery to modern ornithologists; and the world's smallest vertebrate, a species of fish called Paedocypris progenetica. This last wonder, a mere 8mm long, is smaller than a fly and was discovered on Sumatra by an international team that included museum researcher Ralf Britz.
"It's great when you discover something," he said, "especially when it is a creature as tiny and bizarre as this one. But for every day you spend in the field looking for new animals, you have to spend 20 studying what you bring back and working out its relationships with other creatures."
The Natural History Museum provides a home to 70 million different specimens. In terms of biodiversity, there is nothing else like it. In the Darwin Centre, and in the museum's vaults, millions of insects lie pinned to pieces of cardboard, while there is rack after rack of bottles of formaldehyde filled with snakes, dolphins, frogs, dogs, cats, apes and countless other creatures. These specimens are the gold standards of the animal world and provide the basic data that have allowed scientists to unravel the history of natural selection on Earth.
At present, however, Archie is the star of the show. There in a long, thin, perspex tank lies the animal known in legend as the "Kraken", which has featured in a host of adventure stories including 20,000 Leagues Under the Sea and Doctor No. But how long he will retain his number one billing, it is hard to say. Just to one side of his tank, a cylinder contains a 4ft fish: a coelacanth, once thought to have become extinct millions of years ago but discovered-to great media attention - in the Indian Ocean in 1938. Today it gathers dust, while Architeuthis dux hogs the limelight.
1小题>
The message the reception staff at the Natural History Museum wanted to pass is that ______.
A only readers of a book on natural history can see the squid
B they would plead with future visitors to come to see the squid
C future visitors should book in advance before they come to see the squid
D future visitors won't be allowed in the museum before they book
2小题>
Most of the visitors who came to the museum ______.
A went on guided tours in the museum building without seeing the squid
B had seen the squid on TV before they came to the museum
C saw the squid without being guided by the museum staff
D could hardly accept the news that they couldn't see the squid
3小题>
The public ______.
A has shown unusual enthusiasm to the giant squid
B is no longer wondering about the natural world
C expected more natural history programs on TV
D would be bored with any zoological discovery
4小题>
Where was Archie found?
5小题>
What is the name of the program hosted by David Attenborough?
6小题>
How could we describe the feeling people have towards animals?
7小题>
What destroy(s) wildlife? Name one reason.
8小题>
Ralf Britz felt great when he discovered the ______.
9小题>
It usually takes researchers ______ to figure out what they have found in one- day time.
10小题>
The 70 million specimens kept in the Natural History Museum could serve as ______ for scientists to study the animal world.
11小题>
Archie, the star giant squid, still stays on the top of ______.
12小题>
The 4ft fish which was discovered in 1938 attracted ______.
第 2 题:Reading Comprehension(子母填空):
Quantum World
If successful scientific theories can be thought of as cures for stubborn problems, quantum physics was the wonder drug of the 20th century. It successfully explained phenomena such as radioactivity and antimatter, and no other theory can match its description of how light and particles behave on small scales.
But it can also be mind-bending. Quantum objects can exist in multiple states and places at the same time, requiring a mastery of statistics to describe them. Rife with uncertainty and riddled with paradoxes, the theory has been criticised for casting doubt on the notion of an objective reality -- a concept many physicists, including Albert Einstein, have found hard to swallow.
Today, scientists are grappling with these philosophical conundrums, trying to harness quantum's bizarre properties to advance technology, and struggling to weave quantum physics and general relativity into a seamless theory of quantum gravity.
The birth of an idea
Quantum theory began to take shape in the early 20th century, when classical ideas failed to explain some observations. Previous theories allowed atoms to vibrate at any frequency, leading to incorrect predictions that they could radiate infinite amounts of energy -- a problem known as the ultraviolet catastrophe.
In 1900, Max Planck solved this problem by assuming atoms can vibrate only at specific, or quantised, frequencies. Then, in 1905, Einstein cracked the mystery of the photoelectric effect, whereby light falling on metal releases electrons of specific energies. The existing theory of light as waves failed to explain the effect, but Einstein provided a neat solution by suggesting light came in discrete packages of energy called photons -- a brain wave that won him the Nobel Prize for Physics in 1921.
Quantum weirdness
In fact, light's chameleon -- like ability to behave as either a particle or a wave, depending on the experimental setup, has long stymied scientists. Danish physicist Niels Bohr explained this wave-particle duality by doing away with the concept of a reality separate from one's observations. In his "Copenhagen interpretation", Bohr argued that the very act of measurement affects what we observe.
One controversial experiment recently challenged this either/or scenario of light by apparently detecting evidence of both wave- and particle-like behaviour simultaneously. The work suggests there may be no such thing as photons light appears quantised only because of the way it interacts with matter.
Other interpretations of quantum theory of which there are at least half a dozen deal with the measurement problem by suggesting even more far-fetched concepts than .a universe dependent on measurement. The popular many worlds interpretation suggests quantum objects display several behaviours because they inhabit an infinite number of parallel universes. Uncertainty rules
For about 70 years, this wave-particle duality was explained by another unsettling tenet of quantum theory the Heisenberg uncertainty principle. Formulated by Werner Heisenberg in 1927 and recently made more precise, the theory puts an upper limit on knowledge. It says one can never know both the position and momentum of a quantum object measuring one invariably changes the other.
Bohr defeated Einstein in a series of thought experiments in the 1920s and 1930s using this principle, but more recent work suggests the underlying cause of the duality seen in experiments is a phenomenon called entanglement.
Entanglement is the idea that in the quantum world, objects are not independent if they have interacted with each other or come into being through the same process. They become linked, or entangled, such that changing one invariably affects the other, no matter how far apart they are something Einstein called "spooky action at a distance".
This may be involved in superconductivity and may even explain why objects have mass. It also holds promise for "teleporting" particles across vast distance assuming everyone agrees on a reference frame. The first teleportation of a quantum state occurred in 1998, and scientists have been gradually entangling more and more particles, different kinds of particles, and large particles.
Secure networks
Entanglement may also provide a nearly uncrackable method of communication. Quantum cryptographers can send "keys" to decode encrypted information using quantum particles. Any attempt to intercept the particles will disturb their quantum state -- an interference that could then be detected.
In April 2004, Austrian financial institutions performed the first money transfer encrypted by quantum keys, and in June, the first encrypted computer network with more than two nodes was set up across 10 kilometres in Cambridge, Massachusetts, US.
But keeping quantum particles entangled is a tricky business. Researchers are working on how to maximise the particles' signal and distance travelled. Using a sensitive photon detector, researchers in the UK recently sent encrypted photons down the length of a 100-kilometre fibre optic cable. Researchers in the US devised a scheme to entangle successive clouds of atoms in the hopes of one day making a quantum link between the US cities of Washington, DC, and New York.
Lightning-fast computers
Quantum computers are another long-term goal. Because quantum particles can exist in multiple states at the same time, they could be used to carry out many calculations at once, factoring a 300-digit number in just seconds compared to the years required by conventional computers.
But to maintain their multi-state nature, particles must remain isolated long enough to carry out the calculations -- a very challenging condition. Nonetheless, some progress has been made in this area.
1小题>
Quantum physics ______.
A provided medical cures for persisting problems
B first appeared as a wonder drug in the 20th century
C described some phenomena no other previous theories had ever explored
D gave the best description of some behaviors of light and particles so far
2小题>
Quantum physics is a concept that ______.
A is very difficult to understand
B demands abundant statistics to master
C describes the objective nature of the real world
D has been rejected by many scientists
3小题>
Scientists are ______.
A frustrated by the philosophical problems related to quantum physics
B working to make use of quantum in developing technology
C trying to identify quantum's properties
D struggling to clarify how quantum physics and general relativity could form a new theory
4小题>
According to theories before quantum theory, atomic energy could lead to ______.
5小题>
The contribution Einstein has made is that he discovered the ______, and thus solved the problem with new ideas about light
6小题>
Niel Bohr believed that there is a close correlation between the ______ and ______.
7小题>
Niel Bohr developed his theory by using the ______.
8小题>
Recent studies suggest that quantum objects are ______, hence the duality in experiments.
9小题>
In what field(s) has entanglement been applied in practice?
10小题>