In order to find out, I did a small experiment according to what my father said: I took a large piece of plasticine and divided it into four small pieces. Put four eggs and a board vertically on it, and then put two books, Xinhua dictionary and primary school students' compositions. To my surprise, the egg turned out unscathed! I wonder what will happen if the egg falls sideways? I didn't think, but put four eggs across the plasticine. Hey! Unexpectedly, as soon as I put a copy of Xinhua Dictionary, my eggs fell apart! Are these eggs thin shells? Try another egg! But the result is still the same. I thought again: put vertical eggs and horizontal eggs at the same time, and put some plasticine under the horizontal eggs, so that the two eggs will be equal in height. What is the result? I did another little experiment. As a result, I put a good pencil case and a porcelain plate on it, and the eggs lying horizontally broke with a bang.
Why is this? I think about it carefully: is this egg hard at both ends and soft in the middle? Am I right or wrong in this idea? If it is right, why are the two end shells hard and the middle shell soft? ... I suddenly had a lot of questions. Later, I looked through science books, looked up information and asked the teacher, and came to a conclusion that my idea was wrong. The correct answer should be: If you put an egg horizontally, it will break when you press it. If you stand it upright, it won't be fragile. This shows that the strength of the same material depends on the shape. It's like an arch bridge and a peace bridge. The two can bear different weights, and the arch bridge can bear more weight.
After doing this experiment, I have formed a good habit of thinking seriously and trying to understand when I encounter problems.
In recent years, the global average temperature is rising, and we have felt the trend of climate change from human feelings. Scientists all over the world are constantly exploring the reasons for its change. So, how much do we know about this problem?
At first, many scientists suspected that the cause of climate change was caused by the sun's own activities, but this was not the case. A foreign scientist, after counting the activities of sunspots in recent years, clearly pointed out that in recent years, the activities of sunspots are not obvious and active. In this way, Sun was proved innocent. Then, there can only be one answer: this is caused by human activities. In other words, the frequent human activities in recent years have caused today's consequences.
In this case, what kind of harm will climate warming do to human beings? In August this year, CCTV reported that the summit of Mount Qomolangma dropped by 1.3 meters due to climate warming. Mount Everest is the highest mountain range in China, ranking first in the world. Under the threat of global warming, the world iceberg "giant" also succumbed to the rising temperature every year. Once the temperature continues to rise, it will also cause the sea level to rise, causing the lowlands to be flooded, the coast to be eroded, the salinity of surface water and groundwater to increase, affecting the urban water supply, the groundwater level to rise, and the tourism industry to be harmed. In addition, global warming will also affect animals and plants. Climate is the main factor that determines the distribution of biological communities. Climate change can change the adaptability of different species in a region and the competitiveness of different populations in the ecosystem. Animals and plants in nature, especially plant communities, may adapt to the speed of global warming, thus encountering bad luck. Past climate change (such as the ice age) has made many species disappear, and the future climate will make some species disappear in some areas. For example, the Chinese alligator, a rare animal in China, only lives in such narrow areas as Xuancheng, Jingxian and Nanling. If the northern boundary moves northward, the Chinese alligator may become extinct naturally. Global warming has countless impacts on agriculture and human health.
So global warming is not good? Everything has advantages and disadvantages, so does global warming. For example, with the increase of temperature, sub-polar regions may be more suitable for human habitation; Under appropriate conditions, higher carbon dioxide concentration can promote photosynthesis, thus making plants have higher carbon fixation rate, leading to an increase in plant growth, that is, the yield-increasing effect of carbon dioxide, which is a positive impact of global warming.
In addition to the above reasons, the causes of global warming are: atmospheric destruction, serious pollution and greenhouse effect. In this way, we should be more aware that human influence has played an important role in global warming. Therefore, we should pay more attention to this hot land where we live, so as to ensure that human beings will not suffer consequences in the future and their lives will not suffer greater disasters and injuries.