Chapter 1: Science Real science can benefit mankind, while pseudoscience will bring disaster to one side. We study science in order to promote human progress, so we should have a kind and harmonious heart, keep an indifferent and peaceful heart to face science, be kind to science and make good use of it. Finally, I hope everyone can love science, learn science and use science. As long as we study hard and never give up, we will get real science.
One by one, whimsy makes "impossible" a reality, which is the clever use of scientific knowledge by human beings. All scientists have made great discoveries since childhood, and the door of science is always open to children who love to explore. Students, you also strive to make the impossible possible and make our life more exciting!
Walking into science, there are many wonderful things in the scientific community. Observing meteorology, collecting specimens, scientific experiments, popular science activities, life discovery, etc. It's all an exploratory science. Human beings make progress because of science, and science innovates because of human beings. Human can't live without science, and science can't live without human.
Our earth should also be called water polo, because 7 1% of the earth's surface area where we live is occupied by water. The earth is a very bright blue planet, which has a huge amount of water, totaling 65.438+38.6 million cubic kilometers.
Among them, 96.5% are in the ocean; 1.76% is solid in glacier, frozen soil and snow; 1.7% is underground; The rest are scattered in lakes, rivers, atmosphere and organisms. So it can be said that from the sky to the underground, from the land to the ocean, there is a world of water everywhere.
Under the irradiation of sunlight, water evaporates and diffuses in the air, and a part of water vapor is carried over the land by the airflow, which becomes water droplets, clouds, rain or snow and falls to the ground.
Although there is a lot of water on the earth, there is little fresh water, and there is not much water available for human use. Seawater is salty and bitter, so it can't be drunk, irrigated or used for industry. Fresh water accounts for only about 2.6% of the total water, and most of it is frozen in the north-south level and frozen soil far away from human beings, so it cannot be used. Less than 65,438+0% is scattered in lakes, rivers and underground. Compared with all the water bodies in the world, the quantity of fresh water is actually nine Niu Yi hairs.
Chapter 3: Crossing the river without tearing down the bridge Everyone has a small pit in his stomach. Because it looks like eyes, people call it "belly button eye". Have you noticed this little navel? Have you ever hated that this pit is ugly? I didn't like it before, but now I know its history and don't want to be ungrateful anymore.
When we were still in our mother's belly, we had this navel, but at that time, there was an umbilical cord to help us transport food. We are like prisoners in a prison, waiting for the jailer to deliver something, and this jailer is the umbilical cord. Although we all had mouths at that time, we could not eat. At that time, if we really didn't eat, we would "starve to death", which we now call "because our umbilical cord is connected with our mother, which helps us to send nutrition to our stomachs." That umbilical cord is like a grass stalk, which sends nutrition to our stomachs and makes us grow in our mothers' stomachs. But why is our umbilical cord missing now? Only a bare belly button is left. It turns out that we were cut off by the doctor when we were born, because he was useless. You can't get out without cutting it off.
From now on, I think my navel is no longer ugly.