2. After a long period of high pressure and cementation, gravel and sediment re-formed rocks.
These rocks have preserved more historical sites than those mentioned above.
From the "dead" stones, we can see the activities of the earth's crust.
Fossils are the witness of history, which helps us to understand the development process of the earth's history.
The Footprint of Time is the text of the eighth lesson of the eighth grade junior middle school Chinese textbook (revised in the spring of 20 18). This article is a popular science work, the main task of which is to introduce the peculiar function of rocks to record time, aiming at explaining the significance of understanding this peculiar function of rocks and inspiring the enthusiasm of young people to explore the mysteries of nature. The title of the article "Footprints of Time" is borrowed from Gao Shiqi's poem "Uncle Time". The use of personification vividly shows the traces of time hidden in rocks of various shapes and sizes, so as to arouse people's desire for exploration and interest in reading.