A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct (不同的) species
The discovery was made by researchers at York and Harvard universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephants—the Asian elephant, African forest elephant and African savanna elephant
Once they obtained DNA sequences (序列) from two fossils (化石)，mammoths and mastodons， the team compared them with DNA from modern elephants. They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths.
The scientists used detailed genetic analysis to prove that the African savanna elephants and the African forest elephants have been distinct species for several million years. The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths. This result amazed all the scientists.
There has long been debate in the scientific community that the two might be separate species but this is the most convincing scientific evidence so far that they are indeed different species.
Previously, many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species despite the elephants’ significant size differences. The savanna elephant has an average shoulder height of 3.5metres while the forest elephant has an average shoulder height of 2.5metres. The savanna elephant weighs between six and seven tons, roughly double the weight of the forest elephant. But the fact that they look so different does not necessarily mean they are different species. However, the proof lay in the analysis of the DNA.
Alfred Roca, assistant professor in the department of Animal Sciences at the University of Minois, said, “We now have to treat the forest and savanna elephants as two different units for conservation purpose. Since 1950 all African elephants have been conserved as one species. Now that we know the forest and savanna elephants are two very distinct animals, the forest elephant should become a bigger priority (优先)for conservation purpose .”
1.One of the fossils studied by the researchers is that of ________.
A. the Asian elephant B. the forest elephant
C. the savanna elephant D. the mastodon elephant
2.The underlined word “divergence” in paragraph 4means “________”
A. evolution B. exhibition C. separation D. examination
3.The researcher’s conclusion was based on a study of the African elephant’s _____
A. DNA B. height C. weight D. population
4.What were Alfred Roca’s words mainly about?
A. The conservation of African elephants.
B. The purpose of studying African elephants
C. The way to divide African elephants into two units
D. The reason for the distinction of African elephants
5.Which of the following can be the best title for the passage?
A. Naturalist’s Belief about Elephants.
B. Amazing Experiment about Elephants
C. An Unexpected Finding about Elephants
D. A Long scientific Debate about Elephants
高三英语阅读理解中等难度题
A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct (不同的) species
The discovery was made by researchers at York and Harvard universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephants—the Asian elephant, African forest elephant and African savanna elephant
Once they obtained DNA sequences (序列) from two fossils (化石)，mammoths and mastodons， the team compared them with DNA from modern elephants. They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths.
The scientists used detailed genetic analysis to prove that the African savanna elephants and the African forest elephants have been distinct species for several million years. The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths. This result amazed all the scientists.
There has long been debate in the scientific community that the two might be separate species but this is the most convincing scientific evidence so far that they are indeed different species.
Previously, many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species despite the elephants’ significant size differences. The savanna elephant has an average shoulder height of 3.5metres while the forest elephant has an average shoulder height of 2.5metres. The savanna elephant weighs between six and seven tons, roughly double the weight of the forest elephant. But the fact that they look so different does not necessarily mean they are different species. However, the proof lay in the analysis of the DNA.
Alfred Roca, assistant professor in the department of Animal Sciences at the University of Minois, said, “We now have to treat the forest and savanna elephants as two different units for conservation purpose. Since 1950 all African elephants have been conserved as one species. Now that we know the forest and savanna elephants are two very distinct animals, the forest elephant should become a bigger priority (优先)for conservation purpose .”
1.One of the fossils studied by the researchers is that of ________.
A. the Asian elephant B. the forest elephant
C. the savanna elephant D. the mastodon elephant
2.The underlined word “divergence” in paragraph 4means “________”
A. evolution B. exhibition C. separation D. examination
3.The researcher’s conclusion was based on a study of the African elephant’s _____
A. DNA B. height C. weight D. population
4.What were Alfred Roca’s words mainly about?
A. The conservation of African elephants.
B. The purpose of studying African elephants
C. The way to divide African elephants into two units
D. The reason for the distinction of African elephants
5.Which of the following can be the best title for the passage?
A. Naturalist’s Belief about Elephants.
B. Amazing Experiment about Elephants
C. An Unexpected Finding about Elephants
D. A Long scientific Debate about Elephants
高三英语阅读理解中等难度题查看答案及解析
A recent study of ancient and modern elephants has come up with the unexpected conclusion that the African elephant is divided into two distinct (不同的) species
The discovery was made by researchers at York and Harvard universities when they were examining the genetic relationship between the ancient woolly mammoth and mastodon to modern elephants—the Asian elephant, African forest elephant and African savanna elephant
Once they obtained DNA sequences (序列) from two fossils (化石)，mammoths and mastodons the team compared them with DNA from modern elephants. They found to their amazement that modern forest and savanna elephants are as distinct from each other as Asian elephants and mammoths.
The scientists used detailed genetic analysis to prove that the African savanna elephants and the African forest elephants have been distinct species for several million years. The divergence of the two species took place around the time of the divergence of Asian elephants and woolly mammoths. This result amazed all the scientists.
There has long been debate in the scientific community that the two might be separate species but this is the most convincing scientific evidence so far that they are indeed different species.
Previously, many naturalists believed that African savanna elephants and African forest elephants were two populations of the same species despite the elephants’ significant size differences. The savanna elephant has an average shoulder height of 3.5metres while the forest elephant has an average shoulder height of 2.5metres. The savanna elephant weighs between six and seven tons, roughly double the weight of the forest elephant. But the fact that they look so different does not necessarily mean they are different species. However, the proof lay in the analysis of the DNA.
Alfred Roca, assistant professor in the department of Animal Sciences at the University of Minois, said, “We now have to treat the forest and savanna elephants as two different units for conservation purpose. Since 1950 all African elephants have been conserved as one species. Now that we know the forest and savanna elephants are two very distinct animals, the forest elephant should become a bigger priority (优先)for conservation purpose .”
1.
One of the fossils studied by the researchers is that of ________.
A. the Asian elephant B. the forest elephant
C. the savanna elephant D. the mastodon elephant
2.
The underlined word “divergence” in paragraph 4means “________”
A. evolution B. exhibition C. separation D. examination
3.
The researcher’s conclusion was based on a study of the African elephant’s ____________
A. DNA B. height C. weight D. population
4.
What were Alfred Roca’s words mainly about?
A. The conversation of African elephants.
B. The purpose of studying African elephants
C. The way to divide African elephants into two units
D. The reason for the distinction of African elephants
5.
Which of the following can be the best title for the passage?
A. Naturalist’s Belief about Elephants. B. Amazing Experiment about Elephants
C. An Unexpected Finding about Elephants D. A Long scientific Debate about Elephants
高三英语阅读理解中等难度题查看答案及解析
A recent study has come up with _____ unexpected conclusion that ____ Africa elephants should be divided into two different species.
A．a, the B．an, the C．an, an D．the, the
高三英语单项填空中等难度题查看答案及解析
A recent study has come up with _____ unexpected conclusion that ____ Africa elephants should be divided into two different species.
A.a, the B. an, the C. an, an D. the, the
高三英语单项填空简单题查看答案及解析
I recently turned fifty,which is young for a tree,midlife for an elephant,and ancient for a sportsman.Fifty is a nice number for the states in the US or for a national speed limit,but it is not a number that I was prepared to have hung on me.Fifty is supposed to be my father’s age,but now I am stuck with this number and everything it means.
A few days ago,a friend tried to cheer me up by saying,“Fifty is what forty used to be.”He had made an inspirational point.Am I over the hill?People keep telling me that the hill has been moved,and I keep telling them that the high-jump bar has dropped from the six feet I once easily cleared to the four feet that is impossible for me now.
“You’re not getting older,you’re getting better,”says Dr.Joyce Brothers.This,however,is the kind of doctor who inspires a second opinion.
And so,as I approach the day when I cannot even jump over the tennis net,I am moved to share some thoughts on aging with you.I am moved to show how aging feels to me physically and mentally.Getting older,of course,is obviously a better change than the one that brings you eulogies(悼词).In fact,a poet named Robert Browning considered it the best change of all:
Grow old along with me!
The best is yet to be.
Whether or not Browning was right,most of my first fifty years have been golden ones,so I will settle for what is ahead being as good as what has gone by.I find myself moving toward what is ahead with a curious blend(混合)of both fighting and accepting my aging,hoping that the philosopher(哲学家)was right when he said.“Old is always fifteen years from now.”
1.The author seems to tell us in Paragraph 1 that ________.
A.time alone will tell
B.time goes by quickly
C.time will show what is right
D.time makes one forget the past
2.When the author turned fifty,people around him ________.
A.tried to comfort him
B.got inspirations from him
C.were friendlier with him
D.found him more talkative
3.The author considers his fifty years of life ________.
A.peaceful B.ordinary C.satisfactory D.regretful
4.We can infer from the passage that ________.
A.the old should lead a simple life
B.the old should face the fact of aging
C.the old should take more exercise
D.the old should fill themselves with curiosity
高三英语阅读理解极难题查看答案及解析
A recent study has ________an unexpected conclusion that the African elephant should be divided into two different species.
A．kept up with B．made up with C．caught up with D.come up with
高三英语单项填空中等难度题查看答案及解析
(2014·安徽省芜湖三校一模)A recent study has ________an unexpected conclusion that the African elephant should be divided into two different species.
A．kept up with B．made up with
C．caught up with D．come up with
高三英语单项填空简单题查看答案及解析
(2013·四川省宜宾五校二调)A recent study has ________ an unexpected conclusion that the African elephant should be divided into two different species.
A．kept up with B．made up with
C．caught up with D．come up with
高三英语单项填空简单题查看答案及解析
The exact work of ancient astronomers has led to a modern observation --- our days are longer than they used to be. Not that you’d noticed: The new research in the Proceedings of the Royal Society A shows that it takes the Earth a tiny bit longer these days to complete a single rotation (转动) than it did millions of years ago. It’s the kind of stuff that’s measured in milliseconds per century, but those milliseconds add up. Over the last thousands of years, they’d totaled several hours, which the Los Angeles Times puts this way, “If humanity had been measuring time with an atomic clock that started running back in 700 BC, today that clock would read 7 p.m. when the sun is directly overhead rather than noon. The atomic clock won’t lose a second for 15 billion years.” Maybe more remarkable is that the work is the result of a tireless 40-year research into ancient timekeeping records dating back 2,700 years.
Scientists led by Richard Stephenson of the UK’s Durham University have been studying Babylonian clay tablets, Chinese observations made through the use of water clocks, and Arab astronomical records that tracked solar and lunar eclipses(日/月食). “The most astonishing thing about this study is the fact that we have this information at all,” said a geographer not involved in the study. Researchers are still hoping to find observations from the Incas and the Maya, and to fill in their largest hole between 200 and 600 AD, but they’ve measured the Earth’s deceleration at 1.8 milliseconds per day per century. Given the moon’s gravitational effect on our oceans, the discovery that Earth is decelerating isn’t a surprise, notes the Christian Science Monitor, though astronomers had previously estimated a higher rate.
1.Why are days longer than before according to the text?
A. The earth rotates more and more slowly.
B. Humanity has got incorrect timekeeping records.
C. It takes longer for the earth to turn around the sun.
D. The lost milliseconds for centuries are added to our present days.
2.How did researchers come to the conclusion of the study?
A. By resetting the rotating time of the earth.
B. By referring to ancient timekeeping records.
C. By studying the moon’s gravitational effect on the oceans.
D. By measuring time again with an atomic clock.
3.What can we infer about the study from what the geographer said?
A. Geography theory supports the result of the study.
B. The geographer disagrees to the research conclusion.
C. The scientists’ research is meaningless.
D. It’s right to get geographers involved in the study.
4.What is the meaning of the underlined word “deceleration” in Paragraph 2?
A. Evolution. B. Slowdown.
C. Enlargement. D. Development.
高三英语阅读理解中等难度题查看答案及解析
The exact work of ancient astronomers has led to a modern observation --- our days are longer than they used to be. Not that you’d noticed: The new research in the Proceedings of the Royal Society A shows that it takes the Earth a tiny bit longer these days to complete a single rotation (转动) than it did millions of years ago. It’s the kind of stuff that’s measured in milliseconds per century, but those milliseconds add up. Over the last thousands of years, they’d totaled several hours, which the Los Angeles Times puts this way, “If humanity had been measuring time with an atomic clock that started running back in 700 BC, today that clock would read 7 p.m. when the sun is directly overhead rather than noon. The atomic clock won’t lose a second for 15 billion years.” Maybe more remarkable is that the work is the result of a tireless 40-year research into ancient timekeeping records dating back 2,700 years.
Scientists led by Richard Stephenson of the UK’s Durham University have been studying Babylonian clay tablets, Chinese observations made through the use of water clocks, and Arab astronomical records that tracked solar and lunar eclipses(日/月食). “The most astonishing thing about this study is the fact that we have this information at all,” said a geographer not involved in the study. Researchers are still hoping to find observations from the Incas and the Maya, and to fill in their largest hole between 200 and 600 AD, but they’ve measured the Earth’s deceleration at 1.8 milliseconds per day per century. Given the moon’s gravitational effect on our oceans, the discovery that Earth is decelerating isn’t a surprise, notes the Christian Science Monitor, though astronomers had previously estimated a higher rate.
1.Why are days longer than before according to the text?
A.The earth rotates more and more slowly.
B.Humanity has got incorrect timekeeping records.
C.It takes longer for the earth to turn around the sun.
D.The lost milliseconds for centuries are added to our present days.
2.How did researchers come to the conclusion of the study?
A.By resetting the rotating time of the earth.
B.By referring to ancient timekeeping records.
C.By studying the moon’s gravitational effect on the oceans.
D.By measuring time again with an atomic clock.
3.What can we infer about the study from what the geographer said?
A.Geography theory supports the result of the study.
B.The geographer disagrees to the research conclusion.
C.The scientists’ research is meaningless.
D.It’s right to get geographers involved in the study.
4.What is the meaning of the underlined word “deceleration” in Paragraph 2?
A.Evolution. B.Slow down.
C.Enlargement. D.Development.
高三英语阅读理解中等难度题查看答案及解析