I don't remember when someone said that if I was lucky enough to see a meteor, I would make a wish in my heart, because I believe it will bring us good luck.
It is no secret that meteors will realize their wishes. Every time I close my eyes, a picture will come to my mind: diamond-like stars are dotted in the dark sky, and suddenly a shining light flashes across the sky, which is more dazzling than any star ... There are many meteors in summer nights. As long as you keep staring at the sky, you will capture several beautiful scenes, but you often have no time to make a wish. Sometimes I often ask: Will its passing really bring us good luck? If this is really the case, then if you want to live a good life, don't you have to pay the price? Then I hope they will stay in the sky and shine forever, so that everyone can share the beauty it brings, even if they can't get a promise before leaving.
Actually, it's just a good wish. What should go will always go. I don't know when it started, but I like to watch the shining stars in the night sky. I always feel that it seems to be looking at me and even trying to say something to me, and my thoughts are led by it, which seems unrealistic. However, at that moment, it painted a beautiful light with its last enthusiasm. After the last farewell ceremony, it disappeared and my heart sank. Although I appreciate its brilliance, it leaves me with more regrets. I can't help asking: why don't good things last long? But when you think about it, it seems to be an eternal necessity. I think so, because when the meteor disappears, that brilliant light has remained in my heart forever. Anyone who has seen a meteor, no matter how long it takes, will still remember the scene in just a few seconds, but it is very shocking and unforgettable.
I don't know when and where the legend that meteors bring good luck originated. I think it was believed a long time ago that as long as you give your wish to an elf in the sky, it will bring it to this world for you ... now I understand that stars are not falling lights in people's hearts, but sacred hopes.
To tell the truth, I don't really have a pious attitude towards this legend, but if I really meet a meteor, I will make my wish without hesitation. Because I like this legend, I like the mood when I make a wish. And as long as I have the heart, I firmly believe that my wish will come true! In fact, in the end, I want to tell you: it's not the meteor that makes you realize your wish, but yourself! It's also every one of us!
2. It is urgent to give a lecture on popular science knowledge.
Why is a bottle full of water not easy to break? There are two identical glass bottles, one is empty, the other is full of water, and at the same time it falls to the ground from the same height. Which bottle breaks easily? Generally speaking, heavy bottles break easily.
But when the bottle is filled with water, the water in the bottle has another function, which can reduce the deformation of the bottle and make it difficult to break. Most of the broken glass bottles are caused by deformation.
When the empty bottle falls to the ground, the pressure is constantly exerted on the bottle, and the bottle is deformed from the outside to the inside and finally breaks. The bottle is full of water. Because water is incompressible, the deformation is reduced and the bottle is not easy to break.
The bottle is filled with water, and then the cap is tightened, so it is more difficult to break. Have we inhaled the soda? We suck soda through a straw, always thinking that it is our mouth that sucks soda up.
Actually, it's not. It only sucks the air in the straw. As for soda, it is the atmosphere that presses it into the mouth. It turns out that after the air in the straw is sucked away, the soda in the tube is reduced by the air pressure, while the soda in the bottle (outside the straw) is at atmospheric pressure. These two pressures are not equal. If the atmospheric pressure is higher, soda will be pressed into your mouth.
If the soda bottle is covered with a cork and a glass tube is inserted in the cork, you can suck soda from the glass tube once or twice at most, and you will never get soda from the bottle again. The reason is also very simple, because the atmosphere outside the bottle can't enter the soda bottle, and the atmosphere can't press the soda into the mouth.
Can I still drink soda without unplugging the cork? Although it can't be sucked up, can it be blown up? Blowing air into the glass tube is one way. Blowing increases the gas in the bottle and increases the gas pressure in the bottle.
When the pressure of the gas in the bottle increases, the soda will be squeezed out of the glass tube. At this time, as long as the mouth does not leave the glass tube, soda can be drunk. The more you blow into the bottle, the more the pressure increases, and you can drink soda smoothly.
After drinking some soda, the volume of gas in the bottle becomes larger and the pressure decreases, so you can't drink soda. Blow again, and you can continue to drink soda.
Famous saying: 1 Only by obeying nature can we overcome nature. -Darwin 2. Nature is a kind mother and a cruel butcher. -Hugo 3. People often treat the environment around them as a free commodity, spoil it at will and don't know how to cherish it. -Gan Haman 4. The earth has given all people the essence of material things, and in the end, what it gets in return from people is the rubbish of these things. -Whitman 5. Not only can we not force nature, but we must obey it. -Escuman 6. Because of our invasion of nature, we have destroyed the beauty of natural landscape, natural dynamic beauty and natural beauty. -Norman Cousins 7. If you want to live safely, you must have five things: first, purify the air; Second, we must clarify drinking water; Third, we should recycle ditches; Fourth, clean the house; Fifth, there should be plenty of sunshine. Florence nightingale.
3. Lack of popular science knowledge
scientific knowledge
1 During the day, birds are twittering in the branches and flying freely under the blue sky. At night, they should rest, sleep and recover their strength like us, but they sleep in different postures.
The reason why sorbet bubbles is because there is a lot of invisible water vapor in the outside air. When it meets a very cold sorbet, it will liquefy into droplets and surround it when it is cold. It seems that the sorbet is bubbling.
Sunflower stems contain a wonderful auxin. This auxin is very afraid of light. When it is irradiated by light, it will go to the backlight side, and at the same time, the cells on its wide side will multiply rapidly, so the backlight side will grow faster than the light side, which makes the sunflower bend to the optical rotation.
Cicada's shell (exoskeleton) is hard and can't expand with the growth of cicada. When the cicada grows to a certain stage, the cicada's exoskeleton restricts its growth, and the cicada loses its original exoskeleton, which is cicada slough.
First, the bees spit the sweet juice of the flowers they picked into an empty hive. At night, they suck sweet juice into their honey stomachs to make it, and then spit it out and swallow it. It takes 100~240 times to make sweet honey.
We see the stars shining, not because the luminosity of the stars has changed, but because of the occlusion of the atmosphere. The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent, and its transparency will change according to its density. So when we look at the stars through it on the ground, we will see that the stars seem to be flashing.
When we feel tired, a lot of carbon dioxide has been produced in our bodies. When there is too much carbon dioxide, oxygen must be supplemented to balance the needs of the body. Because these residual carbon dioxide will affect our body's functional activities, then the body will send out a protective reaction, so we yawn. Yawning is a deep breathing action, which will let us breathe in more oxygen and expel more carbon dioxide than usual, and it can also eliminate fatigue.
Snakes have many scales, which are the outermost armor on their bodies. Scales are not only used to protect the body, but also to be their "feet". When a snake crawls forward, its body will be S-shaped. Every scale outside the S-shape will tilt upward to help the snake catch the uneven road when it moves forward. These scales cooperate with the muscles of the snake and can push the body forward, so the snake can walk without feet!
There is a substance called melanin in our hair. The more melanin, the darker our hair will be. Without melanin, hair will turn yellow or white. When human beings reach old age, various functions of the body will gradually decline, and the formation of pigments will be less and less, so the hair will gradually turn white.
10 when others scratch ourselves, we will feel itchy and laugh nonstop; However, when we scratch ourselves, we not only don't laugh, but also don't itch. Based on our psychological preparation, the brain will send out a message that there is no danger, and the nerves will relax, so that they will not laugh and itch!
1 1 Looking at the sea, it is often found that the sea water is blue-green. However, when you pick up the sea water, you can only see it as transparent and colorless as old water. It turns out that the seawater itself is not much different from the water we touch every day, and it is also transparent. The green we see is actually a phenomenon caused by the ability of seawater to absorb light. Only green light can be absorbed and reflected by seawater; When the seawater is deep, the green light is also absorbed, and the seawater looks blue.
12 There are hairs on the surface of our skin, and there is a vertical hair muscle under each pore. When we come into contact with nerves (such as anger, fear, cold, etc. ), our body temperature will drop, the vertical hair muscles will contract, which will make our hair stand up and form goose bumps. In addition to keeping warm, this physiological system can make animals look bigger than they really are, thus scaring off enemies.
I want a little knowledge of popular science.
During the day, birds fly freely under the blue sky. At night, they should rest, sleep and recover their strength like us, but they sleep in different postures.
The reason why sorbet bubbles is because there is a lot of invisible water vapor in the outside air. When it meets a very cold sorbet, it will liquefy into droplets and surround it when it is cold. It seems that the sorbet is bubbling.
Sunflower stems contain a wonderful auxin. This auxin is very afraid of light. When it is irradiated by light, it will go to the backlight side, and at the same time, the cells on its wide side will multiply rapidly, so the backlight side will grow faster than the light side, which makes the sunflower bend to the optical rotation.
Cicada's shell (exoskeleton) is hard and can't expand with the growth of cicada. When the cicada grows to a certain stage, the cicada's exoskeleton restricts its growth, and the cicada loses its original exoskeleton, which is cicada slough.
First, the bees spit the sweet juice of the flowers they picked into an empty hive. At night, they suck sweet juice into their honey stomachs to make it, and then spit it out and swallow it. It takes 100~240 times to make sweet honey.
We see the stars shining, not because the luminosity of the stars has changed, but because of the occlusion of the atmosphere. The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent, and its transparency will change according to its density. So when we look at the stars through it on the ground, we will see that the stars seem to be flashing.
When we feel tired, a lot of carbon dioxide has been produced in our bodies. When there is too much carbon dioxide, oxygen must be supplemented to balance the needs of the body. Because these residual carbon dioxide will affect our body's functional activities, then the body will send out a protective reaction, so we yawn. Yawning is a deep breathing action, which will let us breathe in more oxygen and expel more carbon dioxide than usual, and it can also eliminate fatigue.
Snakes have many scales, which are the outermost armor on their bodies. Scales are not only used to protect the body, but also to be their "feet". When a snake crawls forward, its body will be S-shaped. Every scale outside the S-shape will tilt upward to help the snake catch the uneven road when it moves forward. These scales cooperate with the muscles of the snake and can push the body forward, so the snake can walk without feet!
There is a substance called melanin in our hair. The more melanin, the darker our hair will be. Without melanin, hair will turn yellow or white. When human beings reach old age, various functions of the body will gradually decline, and the formation of pigments will be less and less, so the hair will gradually turn white.
10 when others scratch ourselves, we will feel itchy and laugh nonstop; However, when we scratch ourselves, we not only don't laugh, but also don't itch. Based on our psychological preparation, the brain will send out a message that there is no danger, and the nerves will relax, so that they will not laugh and itch!
1 1 Looking at the sea, it is often found that the sea water is blue-green. However, when you pick up the sea water, you can only see it as transparent and colorless as old water. It turns out that the seawater itself is not much different from the water we touch every day, and it is also transparent. The green we see is actually a phenomenon caused by the ability of seawater to absorb light. Only green light can be absorbed and reflected by seawater; When the seawater is deep, the green light is also absorbed, and the seawater looks blue.
12 There are hairs on the surface of our skin, and there is a vertical hair muscle under each pore. When we come into contact with nerves (such as anger, fear, cold, etc. ), our body temperature will drop, the vertical hair muscles will contract, which will make our hair stand up and form goose bumps. In addition to keeping warm, this physiological system can make animals look bigger than they really are, thus scaring off enemies.
5. Primary school student idolize's dream-seeking speech
Leaders, distinguished guests,
Hello everyone! The topic of my speech is "Responsibility pours into education, dedication pursues dreams".
Becoming a teacher is my childhood dream. So, at the crossroads of life, I resolutely chose the profession of teacher. Life in a normal school passes quickly. I stepped onto the three-foot platform with full enthusiasm and abundant energy. Along the way, I understand that education is the most glorious cause under the sun, and responsibility is the glory of education; Teachers are engineers of the human soul, and dedication is the soul of teachers.
If education is compared to a big tree, then the love for the post is its root. I work in an environment where I love and respect my work. Young teachers take root on the platform with enthusiasm, middle-aged teachers work without regrets, and old teachers work silently. The rigorous style of leadership and the professionalism of colleagues made me secretly determined: not to seek fame, but to seek work progress; Do not pursue interests, but seek no regrets in this life.
If education comes from love, it is also based on a responsibility. Parents often say to me, "Teacher, if children don't listen to us, they will listen to you." This is the trust of parents and students, but also reflects a heavy responsibility. Learning to be a teacher is a good example. I have always demanded myself by teachers' professional ethics and always set an example for students everywhere. Only by learning and never getting tired can you teach people never getting tired. I take an active part in business study, listen carefully to every open class, and often take notes, have heated discussions and write my experiences. My research also extends to the Internet. I open my own blog, link the blogs of like-minded people, make time to surf the Internet, enter the space of famous teachers, learn their advanced ideas, learn their scientific methods, learn from others, improve myself, improve myself and educate students wholeheartedly.
I love students, especially those with learning difficulties. I often use my spare time to chat with them, open their hearts, stimulate their interest in learning, and then inject a clear spring of knowledge. I understand that in their eyes, even if I just smile at them and touch their little heads, I will be regarded as great encouragement and recognition by them. I am also the mother of a child, but I can spend only a handful of time with my daughter every day. Whenever I see a little guy clinging to me but unable to accompany her, I will be very sad, but I will be very pleased to see the bright smiles and small progress of the students. I know I have more responsibilities. This is the spirit that teachers love "holding a heart without a blade of grass".
3 Primary School Dream Pursuit Speech 3 Primary School Dream Pursuit Speech
If education is compared to a big tree, then dedication is its branch. 20 15 12 13. I participated in the voluntary blood donation activities organized by the Education Bureau. At that time, I was very thin and weak, and my colleagues around me were very worried about me. I dare not tell my parents about blood donation in Shanghai, but I chose to do so because I am a teacher and an activist who is close to the party organization. I should take the lead and set an example for the teachers and students around me. Giving blood once is what I can do. A few more days' rest will help me recover. For a patient who is in urgent need of blood transfusion, having a blood source means a chance of rebirth. Saving a life means saving a happy family. I think my efforts are well worth it. I tell you with practical actions that dedication is happy and joyful!
Madame Curie famously said, "Humans also need dreamers. They are obsessed with the selfless development of a cause, so they can't pay attention to their own material interests." I think teachers should be dreamers who are obsessed with education. This selfless dedication will surely play the most beautiful music! I want to inspire myself with Madame Curie's famous words: dedicate my responsibility to education and pursue my educational dream with dedication. My speech is over, thank you!
6. Poor knowledge of popular science
speed of light
The Milky Way is too big for light to pass through completely 100000 years. The speed of light is about 186000 km \ sec. The farthest star we can see with the naked eye is actually looking at the past 4 billion years ago. It takes a long time for the light from that star to enter your eyes.
average life span
Time to go to the toilet in a person's life: six months; Time to eat in one's life: three years.
Time spent talking in one's life: ten years time spent sleeping in one's life: twenty-two years.
The growth length of hair in a lifetime: 1000 km The capacity of tears in a lifetime: 65 liters.
Weight of skin desquamation in a lifetime: 47.5 kg. Number of cells produced in a lifetime: 750 trillion.
Lifetime walking distance: 22,500 kilometers
Do you still want to know? I still have a lot of short science knowledge. Then ask, because I don't have time to input so much popular science knowledge now.
My real name is Zuo, thank you.
7. Lack of popular science knowledge
Air pollution mainly refers to the chemical pollution of the atmosphere. There are many kinds of chemical pollutants in the atmosphere, and dozens of them are seriously harmful to human body. The air pollution in China belongs to coal-burning pollution, and the main pollutants are soot and sulfur dioxide, as well as nitrogen oxides and carbon monoxide. These pollutants mainly enter the human body through the respiratory tract, and are directly transported from the blood to the whole body without detoxification of the liver. Therefore, the chemical pollution of the atmosphere is very harmful to human health. This kind of harm can be divided into three types: chronic poisoning, acute poisoning and carcinogenesis.
The concentration of chemical pollutants in the atmosphere of chronic poisoning is generally low, which mainly produces chronic toxic effects on human body. Scientific research shows that chemical pollution in urban air is an important cause of chronic bronchitis, emphysema and bronchial asthma. Acute Poisoning When the factory emits a lot of harmful gases and there is no wind and fog, the chemical pollutants in the atmosphere are not easy to disperse, which will cause acute poisoning. For example, in 196 1 year, three petrochemical enterprises in Niigata, Japan continuously discharged a large number of chemical pollutants such as sulfur dioxide, and windless weather caused asthma among local residents. Later, the local air pollution was controlled and the incidence of asthma decreased.
Carcinogenesis Among the chemical pollutants in the atmosphere, there are polycyclic aromatic hydrocarbons (such as 3,4-benzopyrene) and lead-containing compounds, among which 3,4-benzopyrene has the strongest effect on lung cancer. The smoke produced by burning coal, cars and cigarettes contains a lot of 3,4-benzopyrene. Chemical pollutants in the atmosphere can also fall into water, soil and crops, and be absorbed and enriched by crops, thus endangering human health.
Air pollution also includes biological pollution and radioactive pollution. Biological pollutants in the atmosphere mainly include pathogenic bacteria, mold spores and pollen. Pathogens can make people suffer from infectious diseases such as tuberculosis, and mold spores and pollen can cause allergic reactions in some people. Radioactive pollutants in the atmosphere mainly come from radioactive wastes from the atomic energy industry and medical X-ray sources, which are easy to cause skin cancer and leukemia.