An army scientist has helped solve the decades-old murder mystery surrounding the last Russian czar.
The bones unearthed in a shallow grave definitely are those of Czar Nicholas II, said Lt. Col (Dr.) Victor Weedn at an Aug. 31 news conference. Weedn heads the Armed Forces DNA Identification Laboratory in Rockville, Md., which is involved in identifying skeletal remains of U. S. service members who served in Vietnam, Korea and World War II.
The attempt to identify the czar presented a special challenge. The armed forces lab was the perfect place to perform. the type of genetic testing on old, deteriorating bones that was needed in this case, he said.
Until the announcement, scientists had not been able to say for sure whether the bones were those of the czar.
Russian DNA expert Pavel Ivanov, who with Weedn oversaw a team of U. S. military civilians tasked to identify the remains, reached the same conclusion.
Nicholas and his family were rounded up by the Bolsheviks and executed by firing squad in 1918. Their bodies were dumped into a pool of sulfuric acid 20 miles outside the Ural Mountain city of Yekaterinburg.
The shallow grave was uncovered in 1979. Bone fragments believed to be those of the czar, the Czarina Alexandra and three of their five children were unearthed in 1991.
While investigators were able to positively identify the czarina and the daughters early on, a rare, benign genetic condition that first showed up in his generation did not allow them to make a positive identification of Nicholas II.
Rare mutation the key
In the end, it was that genetic mutation which provided the key to solving the mystery, Weedn said. Nicholas' brother, whose remains were exhumed in July 1994, turned out to have the same mutation in his genetic makeup. It is so rare that it makes the identification absolute, he said.
If Russian authorities accept that finding, it will clear the way for the ceremonial burial of the last emperor of Russia.
But the new evidence did not satisfy all skeptics. Emigre Eugene Magerovsky, a retired Russian military intelligence officer, interrupted the news conference to say he was suspicious of how the bones "suddenly" came to light during the Soviet era.
"The Soviets have always been masters of all kinds of shenanigans," he said. He suggested the investigators may have been given two bones from the same corpse, in which case the DNA would have had to match.
Weedn ruled that out, as the tibia and femur from the same side of each body were used in the testing.
Ivanov, a forensic science professor in charge of identifying the remains of the last czar and his family, brought the femur bones—as well as a blood sample from a living relative— to the Rockville laboratory in June.
Much evidence lost
Years of exposure to minerals in the soil destroyed much of the genetic evidence in the bone, Weedn said. Still, through a painstaking process of grinding up bone, reproducing the genetic material from the dust and comparing the results over and over again, the team was able to reach its conclusion.
One mystery Weedn and Ivanov did not address was that of the czar's daughter, Anastasia. Whether she somehow escaped the Bolsheviks' bullets has been the topic of intense debate for more than half a century. The grave yielded bones from only three of the five daughters. Still unresolved is whether Anastasia or Marie might have survived, along with the sickly heir, Alexis.
Weedn, whose laboratory has tested two women who claimed to be Anastasia, found they were not. A third who sought testing has not sent in blood samples for testing, he added. On-again, off-again pairing
Weedn was approached by Ivanov four years ago about becomi
时间:2023-10-03 16:36:43
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It is()that he has to ask for help.
A . so a big job
B . a so big job
C . a such big job
D . such a big jo
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A user has written a script that is not running correctly and asks an administrator for help. Without adding anything to the script, how can the administrator determine the cause of the problem?()
A . Run the script with an ’sh -x’ in front.
B . Run the script with a ’ksh -v’ in front.
C . Type debug into the command line before running the script.
D . Type ’set -x’ into the command line before running the script.
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My vessel has been in collision and()help.
A . advise
B . needs
C . hopes
D . inform
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A user has written a script that is not running correctly and asks an administrator for help. Without adding anything to the script, how can the administrator determine the cause of the problem?()
A . Run the script with an 'sh -x' in front.
B . Run the script with a 'ksh -v' in front.
C . Type debug into the command line before running the script.
D . Type 'set -x' into the command line before running the script.
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The microscope enables scientists to distinguish an incredible number and variety of bacteria.
A . unavoidable
B . unchangeable
C . unbelievable
D . unpredictable
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3 An ethical hacker helps companies.
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Pit No. 1 of the Terracotta Army has an area of more than 18,000 square meters and is the largest pit.
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Scientists are developing an intelligent robot that can “see” and “touch” and make decisions like human beings.
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the first one to landin Britain with an army.
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Scientists are developing an intelligent robot that can “see” and “touch” and make decisions like human beings.
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Professor Taylor’s talk has indicated that science has a very strong _____ on the everyday life of non-scientists as well as scientists.
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Dr. Lynne Moore is an excellent scientist but lacks the skills required for public promotion.
A.正确
B.错误
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Professor Taylor&39;s talk has indicated that science has a very strong ______ on the everyday life of non-scientists as well as scientists.
A) motivation B) perspective C) impression D) impact
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Scientists are pushing known technologies to their limits in an attempt to ________mo
A.A.extract
B.B.inject
C.C.discharge
D.D.drain
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Scientists are working on programs to predict where and when an earthquake will occur.(翻译)
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This is Mr.Evans,()invention has helped hundreds of deaf people.
A、that
B、whose
C、which
D、whom
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Those scientists were conducting an experiment and expected a good______.
A.effect
B.result
C.consequence
D.affect
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This year's special help for the disabled has concentrated on
A.improving their security.
B.providing them with training programmes.
C.research into their illnesses.
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听力原文:Donating blood plasma has always been a noble pursuit to help those in need. Since last September, there has been an upsurge in blood donations, as the need has become more emphasized and more empathized. But if you've had a tattoo or piercing within the last year, you will more than likely be turned away from any blood bank.
When you go to a blood bank to give plasma, they ask you a series of questions to determine if you are eligible to donate. Obviously, they don't want to risk accepting contaminated blood, so they will ask about your sexual history, current health status and other related questions, including whether or not you have gotten a tattoo or piercing within the last 12 months.
All blood that is donated is screened for disease such as HIV, Hepatitis, Syphilis and other common blood- born ailments.
However, it goes without saying that it is a waste of the blood bank's and the donor's time to harvest blood that is tainted and thus worthless.
So, in order to avoid wasted time, they ask these questions to screen the potential donor. And although even I would be quick to say that tattooing and piercing are much safer than some medical professionals like to indicate, there is still always a chance of getting and carrying a disease unknowingly from a tattoo or piercing, especially Hepatitis. That has been the object of many heated arguments and stringent regulations.
If you should happen to contract a disease from a tattoo or piercing, it should show up in a screening after 12 months, which is the reason for the waiting period. Yes, maybe it's a little over-precautious, but would you want to be the one on the receiving end of dirty blood? If there, is even a chance, it is better to be safe than sorry.
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A.Swim in public pools.
B.Give blood.
C.Over exert yourself.
D.Expose your skin to the sun.
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In charge of an army of seven-thousand men, he______the oriental city for nine months and finally defeated it.
A.intruded
B.haunted
C.besieged
D.possessed
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Oceanography has been defined as "The application of all sciences to the study of the sea". Before the nineteenth century, scientists with an interest in the sea were few and far between.
Certainly Newton considered some theoretical aspects of it in his writings, but he was reluctant to go to sea to further his work.
For most people the sea was remote, and with the exception of early intercontinental travelers or others who earned a living from the sea, there was little reason to ask many questions about it, let alone to ask what lay beneath the surface. The first time that the question "what is at the bottom of the oceans?" Had to be answered with any commercial consequence was when the laying of a telegraph cable from Europe to America was proposed. The engineers had to know the depth profile of the route to estimate the length of cable that had to be manufactured.
It was to Maury of the US Navy that the Atlantic Telegraph Company turned, in 1853, for information on this matter. In the 1840s, Maury had been responsible for encouraging voyages during which soundings were taken to investigate the depths of the North Atlantic and Pacific Oceans. Later, some of his findings aroused much popular interest in his book The Physical Geography of the Sea.
The cable was laid, but not until 1866 was the connection made permanent and reliable. At the early attempts, the cable failed and when it was taken out for repairs it was found to be covered in living growths, a fact which defied contemporary scientific opinion that there was no life in the deeper parts of the sea.
Within a few years oceanography was under way. In 1872 Thomson led a scientific expedition, which lasted four years and brought home thousands of samples from the sea.
Their classification and analysis occupied scientists for years and led to a fivevolume report, the last volume being published in 1895.
The proposal to lay a telegraph cable from Europe to America made oceanographic studies take on ______.
A.an academic aspect
B.a military aspect
C.a business aspect
D.an international aspect
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In charge of an army of seven-thousand men,he____the oriental city for nine months and finally defeated it.
A.intruded
B.haunted
C.besieged
D.possessed
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The scientist played an important part in developing his country’s nuclear power ().A
A.A.process
B.B.profile
C.C.program
D.D.progress
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Scientists have established that influenza viruses taken from man can cause the disease in animals. In addition, man can catch the disease from animals. In fact, a great number of wild birds seem to carry the virus without showing an evidence of illness. Some scientists concluded that a large family of influenza viruses may have evolved in the bird kingdom, a group that has been on the earth 100 million years and is able to carry the virus without contracting the disease. There is even convincing evidence to show that virus strains are transmitted from place to place and from continent to continent by migrating birds.
It's known that two influenza viruses can recombine when both are present in an animal at the same time, the result of such recombination is a great variety of strains containing different H and N spikes. This raises the possibility that a human influenza virus can recombine with an influenza virus from a low animal to produce an entirely new spike. Research is underway to determine if that is the way that major new strains come into being, another possibility is that two animal influenza strains may recombine in a pig, for example, to produce a new strain which is transmitted to man.
According to the passage, scientists have discovered that influenza viruses ______.
A.cause ill health in wild birds
B.do not always cause symptoms in birds
C.are rarely present in wild birds
D.change when transferred from animals to man