河流

Other great rivers are the Congo in Africa and the Mekong in southeast Asia.

其他的大河流有非洲的刚果河和南亚的湄公河。

Originate in China is the largest of the Mekong River flowing through the 1,900 km.

发源于中国的湄公河是最大河流，流经西部1900公里。

Until we clean up the oceans and the rivers of mercury, just don't eat it.

只有等到我们的海洋和河流是干净的时候，我们才可以安心的吃鱼。

Long ago it was called Mesopotamia, which means "the land between the rivers."

很久以前，人们称它为美索不达米亚，意为"河流之间的陆地"。

On the other hand, large bass, walleye and other piscivores were found in only 10 percent of the streams and rivers, yet 57 percent of them met or exceeded the 0.3 microgram level.

在另一方面，大贝司， walleye和其他piscivores发现，只有10 ％的溪流与河流，但57 ％的人达到或超过0.3微克的水平。

As a whole,the notable characteristic of primary productivity in size-fractioned structure was that nanoplankton occupied comparatively significant advantage in Beibu Gulf.Nanoplankton has the largest contribution to gross primary productivity,and picoplankton was the secondary contributor,while microplankton the least.The contribution of microplankton for primary productivity in the north Gulf was more than that in the other waters.Nanoplankton and picoplankton contribute more to the gross primary productivity in offshore deep waters than in inshore shallow waters3.The Beibu Gulf can be divided into three ecoregions:Region-Ⅰis the ecoregion in inshore shallow waters of the north Gulf.In average,the water depth is 18m,DIN is 1.88μmol/L,DIP is 0.20μmol/L,N:P is 9.4:1,dissolved silicate is 5.17μmol/L,the Chl a conentration in surface layer is 2.27mg·m~(-3),the assimilation index in surface layer is 3.80mg/,the primary productivity is 198.78mgC/(m~2·d), and potential fishery production is estimated to be 0.24gC/(m~2·a) according to the primary productivity.The ecoregion is mainly affected by the northern coastal water systems,and may be fit for aquaculture;Region-Ⅱis the ecoregion in offshore deep waters of the north Gulf and the coastal shallow waters to the west Hainan Island.In average,the water depth is 35m,DIN is 2.01μmol/L,DIP is 0.18μmol/L,N:P is 11.2:1,disovled silicate is 4.23μmol/L,the chlorophyll a of surface layer concentration is 1.45mg·m~(-3),the assimilation index of surface layer is 4.12 mg/,the primary productivity is 276.60mgC/(m~2·d),and the estimated potential fishery production is 0.34gC/(m~2·a) according to the primary productivity. The ecoregion was mainly influenced by ocean current from the South China Sea, rivers in the west coast of Hainan Island and the water from Qiongzhou Strait.It may be fit for aquaculture and fishery;Region-Ⅲis the ecoregion in offshore deep waters of the mid and south Gulf.In average,the water depth is 75m,DIN is 0.77μmol/L, DIP is 0.15μmol/L,N:P is 5.1:1,disovled silicate is 3.05μmol/L,the chlorophyll a of surface layer concentration is 0.70mg·m~(-3),the assimilation index of surface layer averaged is 3.69mg/,the primary productivity is 350.89mgC/(m~2·d),and the estimated potential fishery production is 0.43gC/(m~2·a) according to the primary productivity.The ecoregion was mainly affected by the circulation inside Beibu Gulf, and may be fit for fishery.

初级生产力的粒级结构的一个显著特点是总体上微型浮游生物在全调查海区均占较明显优势，对总初级生产力的平均贡献最大；微微型浮游生物对初级生产力的平均贡献次之；小型浮游生物对总初级生产力的平均贡献最小；湾北部小型浮游生物对初级生产力的平均贡献高于湾中部和湾南部，而湾中部和湾南部微型和微微型浮游生物对初级生产力的平均贡献高于湾北部，远岸深水区高于近岸浅水区。3、北部湾可以分为三个生态区：湾北部近岸浅水区，该区的环境主要特点是平均水深19m，DIN浓度平均值为1.88μmol/L，DIP浓度平均值为0.20μmol/L，N：P为9.4：1，硅酸盐浓度平均值为5.17μmol/L，表层叶绿素a平均值高达2.27 mg·m~(-3)，表层同化指数平均为3.80 mg/，初级生产力平均值198.78mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.24 gC/(m~2·a)，该区主要受湾北部沿岸水系影响，适合作为水产养殖区；湾北部深水区和海南岛西部沿岸浅水区，该区的环境主要特点是平均水深35m，DIN浓度平均值为2.01μmol/L，DIP浓度平均值为0.18μmol/L，N：P为11.2：1，硅酸盐浓度平均值为4.23μmol/L，表层叶绿素a平均值1.45 mg·m~(-3)，表层同化指数平均为4.12mg/，初级生产力平均值276.60 mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.34 gC/(m~2·a)，该区主要受南部湾口区海流向湾内延伸，沿岸海南岛河流注入湾内和琼州海峡过道水的影响，适合作为渔业作业区和水产养殖区；湾中部和南部远岸深水区，该区的环境主要特点是平均水深75m，DIN浓度平均值为0.77μmol/L，DIP浓度平均值为0.15μmol/L，N：P为5.1：1，硅酸盐浓度平均值为3.05μmol/L，表层叶绿素a平均值0.70 mg·m~(-3)，表层同化指数平均为3.69 mg/，初级生产力平均值350.89 mgC/(m~2·d)，根据初级生产力计算潜在渔业资源碳生产量平均为0.43 gC/(m~2·a)，该区主要受北部湾环流影响，适合作为渔业作业区。

Forecasters warn many rivers in the nation's midsection could crest above flood stage in the coming days.

天气预报员警告说，在接下来的几天里全国中部的河流水位将达到最大洪水位。

Another pecie of advice is, do not change horses in midstream.

另一条建议是，不要在河流中间换马。

Every river has a upstream, midstream and downstream.

每条河流都有上游，中游，下游。

You can create different sorts of bridges from ones that just cross narrow ravines and rivers using logs or just rocks, to the extremely huge mile-long suspension bridges of today''s time.

您可以创建不同类型的桥梁，从那些刚刚跨狭窄，沟壑和河流的使用记录或只是岩石，以极其巨大的英里长的悬索桥的today'的时间。

Do you know, i need you to come back

你知道吗，我需要你回来

Yang yinshu、Wang xiangsheng、Li decang,The first discovery of haemaphysalis conicinna.

1〕 杨银书，王祥生，李德昌。安徽省首次发现嗜群血蜱。