Even ancient Egypt’s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilisation around 2180 BC. Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometres to the south was ultimately to blame — and the same or worse could happen today.
The ancient Egyptians depended on the Nile’s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have diminished these floods.
Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablise the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile.
The Blue Nile mud has a different isotope signature from that of the White Nile. So by analysing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.
Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4,500 to 4,200 years ago, immediately predates the fall of the Egypt’s Old Kingdom.
The weakened waters would have been catastrophic for the Egyptians. "Changes that affect food supply don’t have to be very large to have a ripple effect in societies, " says Bill Ryan of the Lamont Doherty Earth Observatory in New York.
Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D. C. "Anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /
Which of the following statements is true

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nile.

Even ancient Egypt’s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilization around 2180 BC Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame-and the same or worse could happen today.
The ancient Egyptians depended on the Nile’s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have been diminished these floods.
Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablise the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile.
The Blue Nile mud has a different isotope signature from that of the White Nile. So by analyzing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.
Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4500 to 4200 years ago, immediately predates the fall of the Egypt’s Old Kingdom.
The weakened waters would have been catastrophic for the Egyptians. "Changes that affect food supply don’t have to be very large to have a ripple effect in societies," says Bill Ryan of the Lamont Doherty Earth Observatory in New York.
Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D.C. "anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /
Which of the following statements is true ______

A:The White Nile is the trunk of the River Nile. B:The white Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nil

{{B}}第二篇{{/B}}

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nile.

? ?下面有3篇短文，每篇短文后有5道题，每题后面有4个选项。请仔细阅读短文并根据短文回答其后面的问题，从4个选项中选择1个最佳答案。
{{B}}第一篇{{/B}}

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nile.

Even ancient Egypt’s mighty pyramid (金字塔) builders were powerless in the face of the famine (饥荒)that helped bring down their civilization around 2180 B．C.. Now evidence collected from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame and the same or worse could happen today.
The ancient Egyptians depended on the Nile’s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons (季风) southwards out of Ethiopia would have reduced these floods.
Declining rains in the Ethiopian highlands would have meant fewer plants to stabilize the soil. When rain did fall it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment (沉积) from the White Nile.
Blue Nile mud has a different isotope (同位素) signature from that of the white Nile, so by analyzing isotope differences in mud deposited in the Nile Delta Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.
Krom reasons that during periods of drought, the amount of Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4500 to 4200 years ago, immediately came before the fall of the Egypt’s old Kingdom.
The weakened waters would have been disaster for the Egyptians. " Changes that affect food supply don’t have to be very large to have a ripple (波浪) effect in societies. " says Bill Ryan of the Lamont Doherty Earth Observatory in New York.
"Similar events today could be even more devastating," says team member Daniel Stanley, a scientist from the Smithsonian Institution in Washington D.C.. "Anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /
Which of the following statements is true

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile is a branch of the River Nile.

Even ancient Egypt’s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilization around 2180 BC．Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame-and the same or worse could happen today.
The ancient Egyptians depended on the Nile’s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have been diminished these floods.
Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablise the soil. When rain did fail it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile.
The Blue Nile mud has a different isotope signature from that of the White Nile. So by analyzing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.
Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4500 to 4200 years ago, immediately predates the fall of the Egypt’s Old Kingdom.
The weakened waters would have been catastrophic for the Egyptians. "Changes that affect food supply don’t have to be very large to have a ripple effect in societies, " says Bill Ryan of the Lamont Doherty Earth Observatory in New York.
Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D. C. "anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /
Which of the following statements is true

A:The White Nile is the trunk of the River Nile. B:The white Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nile.

? ?Even ancient Egypt’s mighty pyramid builders were powerless in the face of the famine that helped bring down their civilization around 2180 BC．Now evidence gleaned from mud deposited by the River Nile suggests that a shift in climate thousands of kilometers to the south was ultimately to blame-and the same or worse could happen today.
? ?The ancient Egyptians depended on the Nile’s annual floods to irrigate their crops. But any change in climate that pushed the African monsoons southwards out of Ethiopia would have been diminished these floods.
? ?Dwindling rains in the Ethiopian highlands would have meant fewer plants to stablise the soil. When rain did fail it would have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile.
? ?The Blue Nile mud has a different isotope signature from that of the White Nile. So by analyzing isotope differences in mud deposited in the Nile Delta, Michael Krom of Leeds University worked out what proportion of sediment came from each branch of the river.
? ?Krom reasons that during periods of drought, the amount of the Blue Nile mud in the river would be relatively high. He found that one of these periods, from 4500 to 4200 years ago, immediately predates the fall of the Egypt’s Old Kingdom.
? ?The weakened waters would have been catastrophic for the Egyptians. "Changes that affect food supply don’t have to be very large to have a ripple effect in societies, " says Bill Ryan of the Lamont Doherty Earth Observatory in New York.
? ?Similar events today could be even more devastating, says team member Daniel Stanley, a geoarchaeologist from the Smithsonian Institution in Washington, D. C. "anything humans do to shift the climate belts would have an even worse effect along the Nile system today because the populations have increased dramatically. /

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The white Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile and the Blue Nile are branches of the River Nile.

{{B}}第二篇{{/B}}

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile is a branch of the River Nile.

{{B}}第二篇{{/B}}

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile is a branch of the River Nile.

{{B}}第三篇{{/B}}

Which of the following statements is true?

A:The White Nile is the trunk of the River Nile. B:The White Nile is the trunk of the Blue Nile. C:The White Nile is a branch of the Blue Nile. D:The White Nile is a branch of the River Nile.