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- Any of various large, segmented aquatic arthropods of the order Eurypterida that existed from the Ordovician Period to the Permian Period. （古生）板足鲎目的一种巨大的、有节的，属于板足鲎目的水生节肢动物，生存于奥陶纪到二叠纪时期
- The generation of hydrocarbons of the Ordovician source is different from that of Mesozoic nd Cenozoic sources since there were on high plants in the Ordovician Period. 由于当时没有高等植物出现，因此奥陶系烃源岩在油气生成上与我国东部中、新生界陆相烃源岩有着明显的不同。
- Five past extinctions: Some event near end of the Ordovician period, 440m years ago, wiped out almost all corals and fish, and 25 % of all families of creatures. 历史上曾发生过的5次物种大灭绝：4．4亿年前奥陶纪将要结束时的一些事件使几乎所有的珊瑚和鱼类以及25%25的物种灭绝；
- Benxi water tunnel in the limestone is the Ordovician period under the EC-Hill Group and the EC in the Majiagou group, the role of a rock from development. 本溪水洞的石灰岩就是在这个时期的奥陶系下统亮山组和中统马家沟组时，经过岩化作用发育而成。
- Bachu arch,one of hydrocarbon abundance units in Tarim basin,has experienced a series of rise and denudation as well as drop and sedimentation since Ordovician period. 巴楚凸起是塔里木盆地油气富集单元之一,自奥陶纪以来经历了多次隆升剥蚀与下降沉积的交替过程,经喜马拉雅运动期的断裂褶皱、抬升剥蚀,定型为塔西南前陆盆地的前缘隆起。
- The forming of Sichuan Basin was closely relation with ancient geography and geological structure. Besides Yushan salt spring of Pengshui belonged to Ordovician period, others were mainly distributed to the layers of Jurassic and Triassic period. 四川盆地盐矿形成与古地理环境和地质构造密切相关,除了彭水郁山盐泉来自奥陶纪地层外,其余主要分布于侏罗纪、三叠纪岩层。
- Online access to the museum's catalogues is provided including databases for fossils, the Cambrian period, the Ordovician period, rock specimens, and the MacCulloch database of geological specimens. 还有一些岩石标本及地质学标本。
- Enrichment of Au during the Ordovician period; 奥陶系富集Au;
- STRATIGRAPHIC CLASSIFICATION OF THE ORDOVICIAN PERIOD OF GUILIN 桂林奥陶纪地层的划分
- That period was a bright page in the history of Chinese literature. 那个时期是中国文学史上光辉的一页。
- Let us hope that the period of this injustice will be over soon. 让我们希望这个不公正的时期很快结束吧。
- Childhood is a period of rapid growth. 幼年是生长迅速的时期。
- He consulted the chronicles of the period. 他参考了这一时期的编年史。
- Keywords ordovician period;gas field;acidizing effect;pressure buildup curve; 奥陶纪;气田;酸化效果;压力恢复曲线;
- He had to decide within a given period. 他得在一定时间内作出决定。
- She has a detailed knowledge of this period. 她对这段时期的情况了解地相当详细。
- In that period auto sales hit a14-year low. 这时期汽车销售量达到14年来最低水平。
- In this period, unemployment reaches record levels. 这段时间的失业人数又达到了创纪录水平。
- Which period of history are you studying? 你正在学哪一段历史？
- Can you tell me the time period when it was stolen? 能不能告诉我大概什么时候被偷的？
