[an error occurred while processing this directive]
17、 around 2180BC. 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 blem -- and the same or worse could happen today. the African monsoons southwards out of Ethiopia would have diminished these floods. have washed large amounts of soil into the Blue Nile and into Egypt, along with sediment from the White Nile. 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 Egypts Old Kingdom. large to have a ripple effect in societies, says Bill Ryan of the Lamont Doherty Earth Observatory in New York. Smithsonian Institution in Washington, D.C.. Anything humans do to shift the climate belts would have an even worse effect along the Nile system because the populations have increased dramatically. |
辅导科目名称 |
基础班 |
精讲班 |
冲刺班 |
考题预测班 |
|||||
类别 |
级别 |
课时 |
试听 |
课时 |
试听 |
课时 |
试听 |
课时 |
试听 |
AB级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
C级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
AB级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
C级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
AB级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
C级 |
22讲 |
40讲 |
20讲 |
10讲 |
|||||
热门资料下载: |
职称英语考试论坛热贴: |
【责任编辑:育路编辑 纠错】 |
|
阅读上一篇:职称英语等级考试综合类AB级试题及答案4 |
|
|