单词：alluvial sediments
(alluvial sediment 的复数)
单词：alluvial sediments 相关文章
This is Scientific American's 60-Second Science. I'm Cynthia Graber. This will just take a minute. Theres a Native American site in Ohio that appeared to be a fort. But recent discoveries by archaeologists at the University of Cincinnati show thats n
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Conservation Project at Risk from Mai Mai Attack The hunt continues for the Mai Mai militia that attacked a DRC conservation project in June. Six people were killed, as well as 14 endangered animals called Okapi, or forest giraffe. The attack occurre
VOA标准英语2012年(七月)
Better known for its diamond fields, gold exploration and mining in Sierra Leone is on the increase. The British company, Cluff Gold, has announced it will build a mechanized gold mine in the southern Kangari hills after finding large deposits of gol
VOA标准英语2010年(四)月
They may be a little safer here. But the food in the forest is far less nutritious than on the riverbanks. If they want to eat well and avoid wolves this winter, they'll need to keep on moving. As the elk move gradually downwards, they follow the riv
自然百科2012年
By Naomi Schwarz Dakar 04 December 2007 Diamonds from Sierra Leone have fueled the country's gruesome civil war and enriched warlords. Now, the government and activists are trying to make sure the profits from Sierra Leone's post-conflict diamonds he
VOA常速英语2007年（十二月）