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Anonymous users2024-02-10Part 1 (1): Introduce the appearance and characteristics of fossilized bones of Yellow River elephants.
Part 2 (2-4): Scientists hypothesize the origin of fossils.
Part 3 (5): Fossils of the Yellow River elephant are excavated.
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Anonymous users2024-02-09Sorry, it's 10 natural segments. Is it?
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Anonymous users2024-02-08The Yellow River Elephant is a (scientific essay) written by a scientist who hypothesized the formation process of an ancient Yellow River elephant skeleton displayed in the paleontology hall of the Beijing Museum of Natural History based on the scene (during the excavation of the Yellow River elephant) and the scientific knowledge (of fossil formation), showing that (paleontological fossils) are reliable evidence of the evolution of nature. Just hit the air and separate it with punctuation!
The text can be divided into four parts according to different aspects.
The first part (paragraph 1) describes the Yellow River elephant skeleton fossil cover: tall and complete.
The second part (paragraphs 2 and 6) writes that scientists hypothesize the formation process of fossilized bones of the Yellow River elephant. This part of the text is the focus of the text, and the fourth natural paragraph is particularly important, especially to guide students to give full play to their imagination and vividly express the scene of the old elephant falling into the mud.
The third part (paragraph 7) writes about the changes in the earth's crust.
The fourth part (paragraph 8) describes what people saw when they discovered and excavated fossilized bones of the Yellow River elephant, as well as the imagination and reasoning of scientists.
The author of this article also shows ingenuity in arranging the material, and it is necessary to learn how to express it. The author first wrote that the fossilized bones of the Yellow River elephant on display at the Beijing Museum of Natural History are tall and complete, so as to arouse the curiosity of readers. Next, I wrote the story of the imaginary Yellow River elephant falling into the water and becoming a fossil of grinding Zen noise, which is vivid and interesting to read.
Then explain the changes in the earth's crust to make the story more scientific. Finally, he writes about the scene that people saw with their own eyes during the excavation, and points out the basis for the hypothesis. Arrange the material in this way to receive an engaging expression.
The four parts of the text can be arranged in other orders. For example, write first.
Part 2 and 3, then the first part, and then the fourth part; It is also possible to write the fourth part first and the first part last.
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Anonymous users2024-02-07Yesterday I read an article entitled "The Yellow River Elephant", which describes the morphology of the skeleton of the Yellow River elephant and the excavation process of this elephant fossil, and explains the origin of the Yellow River elephant fossil from the perspective of scientists. Reading it has given me an increase in my knowledge about fossil production. In the paleontology hall of the Beijing Museum of Natural History, the skeleton of an elephant is on display, which is the fossil of the skeleton of the Yellow River elephant.
The elephant skeleton is 4 meters tall and 8 meters long, and all but the tail vertebrae are mounted from fossilized bones. The skeleton of the ancient Yellow River elephant can be preserved in such a complete way, which is rare in the history of elephant fossil discovery. Fossils are the relics of ancient creatures buried in the strata.
The most common fossils are formed from teeth and bones. After the death of ancient animals, the internal organs, muscles and other soft tissues of the corpse will quickly decay, and the teeth and bones can be preserved for a longer time because there is less organic matter and more inorganic matter. If the body happens to be buried in sediment, cut off from the air, the process of decay slows down.
Over time, the weight of the bones increases, and the original teeth and bones become stones that still preserve the original shape and internal structure of the teeth and bones, a process called "petrification".
In addition to teeth and bones, the feces of some animals can also be fossilized. For example, some carnivores eat meat with broken bones, and there are many undigested broken bones in the feces, which are not easy to decay, so they can become fossils. Footprints can also become fossils.
People or animals step on the mud and sand, causing footprints. When the sediment dried, the footprints were filled with other substances. Both substances are preserved by the petrification of minerals that later seep in, but the properties of the two substances are different, the hardness is different, and the degree of weathering or destruction is also different.
When one substance is weathered or destroyed, the other appears as fossilized footprints.
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Anonymous users2024-02-06This one is very simple. How much will you pay??
1. Work information:
The Elephant of the Yellow River is a lecture and reading text in the second group of the nine volumes of the old edition of primary school Chinese. It is a literary and artistic science sketch, selected from the "Juvenile Science Series" "The Story of the Elephant". Author: Liu Houyi. >>>More
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The Yellow River elephant is the world's best-preserved elephant and the largest elephant fossil ever found in Asia, with a height of meters and a total skeleton length (the drooping part of the incisors from the base to the tail). It is also the most well-preserved elephant fossil found in the world, and the skeleton of its whole body is only the hanging tail that has not been found. Scientists have analyzed that it may have left its tail exposed when it sank into the sediment, so it decomposed and was not preserved as a fossil.
The increasingly serious water pollution of the Yellow River has seriously damaged the Yellow River ecosystem, resulting in the endangerment of aquatic life in the river. In the fifties of the last century, the beach of Yantan in Lanzhou City was full of red willows and reeds, and more than a dozen kinds of water birds such as bar-headed geese and plateau partridges inhabited, and now there is no trace of these bird species. In the early sixties of the last century, the number of fish growing in the Gansu section of the Yellow River was greatly reduced, and some of them have become extinct. >>>More
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