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Anonymous users2024-02-07There are four historical periods of 4.6 billion years old, and dinosaurs are indeed 60 million years old.
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Anonymous users2024-02-06The Earth is about 4.6 billion years old. The universe was born 15 billion years ago, laying the material foundation for the creation of the earth. The Earth as a planet originated from the primordial solar nebula 4.6 billion years ago.
Since then, the Earth system has evolved from simple to complex, and the evolution of its components is both interconnected and mutually influential. The movement of the earth system and the resulting changes in the landscape, life phenomena and life activities together constitute the history of the earth.
The systematic scientific study of the question of the origin and evolution of the earth began in the middle of the eighteenth century, and several theories have been put forward to this day. It is generally believed that the Earth, as a planetary leaky star, originated from the primitive solar nebula 4.6 billion years ago. Earth, like other planets, has undergone a number of common physical evolutionary processes, such as accretion and collision.
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Anonymous users2024-02-05The geo-geological chronology of the first year of high school is as follows:
Phanerozoic. 1. New generation.
1) Quaternary.
It began millions of years ago. During the Ice Age, a large number of large mammals became extinct and humans were born.
2) Neogene.
It began millions of years ago. The ancestors of mankind - great apes appeared.
3) Paleogene.
a) Started millions of years ago. Most of the mammalian order rises.
b) Started millions of years ago. Angiosperms thrive.
2. Mesozoic.
1) Cretaceous.
It began millions of years ago. Extinction event at the end of the Cretaceous period: a large number of creatures such as dinosaurs became extinct, and mammals with placentas appeared.
2) Jurassic.
It began millions of years ago. Birds appeared, marsupial mammals appeared, dinosaurs flourished, angiosperms appeared, gymnosperms flourished.
3) Triassic.
It began millions of years ago. Dinosaurs appeared, Pangea (pan-continent) was formed, and oviparous mammals appeared.
3. Paleozoic.
1) Permian.
It began millions of years ago. 95% of the earth's life is extinct, and the outline of Pangea is emerging.
2) Carboniferous.
It began millions of years ago. Reptiles appeared, insects flourished. Gymnosperms appear, ferns flourish, coal-forming period.
3) Devonian.
It began millions of years ago. Amphibians appeared, fish flourished, insects appeared. Lycopodium and horsetail appear, and seed plants appear.
4) Silurian period.
It began millions of years ago. Terrestrial naked ferns appear.
5) Ordovician.
It began millions of years ago. Fish appear, seaweed flourishes.
6) Cambrian.
It began millions of years ago. The Cambrian explosion of life.
4. Precambrian.
1) Started 630+5 -30 million years ago.
Multicellular organisms emerge.
2) Started 2300 million years ago.
Cyanobacteria and bacteria flourish.
3) Started 2500 million years ago.
Ironogenic (important iron ore metallogenic period).
4) Started 3600 million years ago.
Blue-green algae appear.
5) Started 3850 million years ago.
The earliest living things on earth appeared - bacteria.
6) Started 4150 million years ago.
Oceans appear on Earth.
7) Started 4570 million years ago.
Earth Formation.
In ancient times, humans have used fragrances to change the smell of the human body, and the use of fragrances and the origin of patented perfumes as the upper class of rulers have been forgotten with the passage of time. If the widespread use of fragrance technology under the influence of the Orientals opened the first page in the history of perfumery, then it was the distillation process invented by the Arabs that made a new contribution to the development of perfumery. Next, the Crusades led to the discovery of essential oils by the French, and thus established the supremacy of France in the perfume kingdom today. >>>More
In the third century B.C., Maneto divided the history of Egypt from Menes to the conquest of Alexander in Macedon into thirty (or thirty-one) dynasties, on the basis of which scholars now divide the history of ancient Egypt into the following periods: 1 Predynastic period (period of gold and stone, c. 4500-3100 B.C.) 2 Early dynastic period (1-2 dynasties, c. 3100-2680 B.C.) 3 Old Kingdom period (3-6 dynasties, c. 2686-2181 B.C.) 4 First Intermediate Period (7th-10th Dynasty, c. 2181-2040 B.C.) 5 Middle Kingdom Period (11th-12th Dynasty, c. 2040-1786 B.C.) 6 Second Intermediate Period (13th-17th Dynasty, c. 1786-1567 B.C.) 7 New Kingdom Period (18th-20th Dynasty, c. 1567-1085 B.C.) 8 Later Dynastic Period (21th-31st Dynasty, c. 1085-332 B.C.) 9 Macedonian Greeks and Romans (332 BC – 642 AD) The 1st to 4th periods were the period of the formation of slave states and the emergence of unified dynasties, the 5th to 7th periods were the period of the re-establishment of the unified kingdom and the empire, and the 8th to 9th periods were the period of the decline of the slave states of Egypt and the fall under foreign rule. Thank you for your support to this team for about 6500 years now.
1. It has a long history
The Great Wall of Qin was built in the 3rd century BC and has a long history, with a history of more than 2,300 years. If you go back to the Great Wall of the Western weekend and the Spring and Autumn Period and the Warring States Period, the Great Wall of China is at least 2,700 years old. Even the Great Wall built in the Ming Dynasty is more than 600 years old. >>>More
Created about 4,000 years ago, Chinese characters are the most spoken script in the world, and have had an important impact on the writing of Japan, Korea and other countries. Chinese calligraphy is a unique art. Throughout the ages, many famous calligraphers have emerged in our country, and their calligraphy works are treasures of art!
Stage 1: The Origins of Ballet.
The second stage: the prototype of ballet (i.e., the French court comedy ballet, opera ballet period) The third stage: pre-romantic ballet. >>>More