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发表于 2009-6-25 19:45
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本帖最后由 waahuaa 于 2009-6-25 19:56 编辑
话说为何无线上网不能登陆qq？
只能开网页，晕
再补充1坨关于多样性分布中心的说明：
A center of diversity is an area that has a high degree of genetic variation for a particular species or genus of plants that can also be the center of origin for that species. The two areas often, but not always, coincide; the degree of coincidence remains the subject of debate.[1][2] In both areas, organisms have had the opportunity over many generations to evolve resistance, via mutation, to their pathogens.[1]
The term was created by the Russian scientist Nikolai Vavilov and the U.S. scientist Jack Harlan.[3] Vavilov published a study in 1926 (Studies on the Origin of Cultivated Plants) describing ten such centers:
- 1 - China for lettuce, rhubarb, soybean, and turnip;
- 2 - India for cucumber, rice, mango, and Asian cotton;
- 2a - Indochina for banana, coconut, and rice;
- 3 - Central Asia (north India, Afghanistan, and Turkmenistan) for almond, flax, and lentil;
- 4 - Near East for alfalfa, apple, cabbage, and rye;
- 5 - Coastal and adjacent areas of the Mediterranean Sea for celery, chickpeas, and durum wheat;
- 6 - Ethiopia for coffee, grain sorghum, and pearl millet;
- 7 - Southern Mexico and Middle America for maize, lima bean, papaya, and upland cotton;
- 8 - Northeastern South America (Bolivia, Ecuador, and Peru) for potato, tomato, and Egyptian cotton;
- 8a - Isles of Chile for potato.[3]
Vavilov later modified the concept to include secondary centers of diversity.[2]
[url=][/url]
[edit] References
[edit] See also
出处：http://en.wikipedia.org/wiki/Center_of_diversity
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狗仔卡
发表于 2009-6-25 19:42
组图打开中，请稍候......
提升卡
变色卡
显身卡
猛一看好像美花酢，从那么小养起来真不容易