1. For example, water should be boiled to 1 degrees.
2. The straw feels crooked in the water, which is the refraction of water.
3. The food in canned food is not easy to go bad, and they can be stored for a long time without going bad. This is because the can is sealed, so bacteria can't enter.
4. Sunflower always blooms towards the sun, and there is a substance called "auxin" in the stem under the sunflower disk. This substance has the function of accelerating reproduction, but it is anti-optical, and whenever it encounters light, it will run to the backlight side.
Science means learning by subjects, and later refers to the gradual formation of a complete knowledge system through detailed classification (such as mathematics, physics, chemistry, etc.). It is a knowledge about the practice of discovery, invention and creation, and it is the general name of the knowledge system that human beings explore, study and understand the changing law of all things in the universe.
2. Little scientific knowledge in life
Why do the stars twinkle? We see the stars shining, not because the luminosity of the stars themselves changes, 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 the density.
So when we look at the stars through it on the ground, we will see that the stars seem to be flashing. 2. Why do people yawn? 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 added to balance the body's needs. Because these residual carbon dioxide will affect the functional activities of our body, then the body will send out a protective reaction, so it yawns.
yawning is a deep breathing action, which will make us breathe in more oxygen and expel carbon dioxide than usual, and it can also eliminate fatigue. 3. Why can snakes walk without feet? Snakes have many scales, which is the outermost layer of armor on their bodies.
Scales are not only used to protect the body, but also can be their "feet". When a snake crawls forward, its body will be S-shaped.
And every scale outside the S-shape will tilt up to help the snake catch the uneven road when it moves forward. These scales cooperate with the snake's muscles and can push the body forward, so the snake can walk without feet! 4. Why do sunflowers always bloom towards the sun? There is a substance called "auxin" in the stem under the sunflower disk.
This substance has the function of accelerating reproduction, but it is anti-optical. Whenever it meets light, it will run to the backlight side. So when the sun rises, the stem of the sunflower immediately hides to the backlight side, and it seems that the whole plant bends in the direction of the sun.
5. Why does hair turn white when people get old? There is a substance called melanin in our hair. The more melanin there is, the darker our hair will be. If there is less melanin, the hair will turn yellow or white.
When people get old, all kinds of functions of the body will gradually decline, and the formation of pigment will be less and less, so their hair will gradually turn white! 6. Why do fireflies glow? Fireflies emit light because there is a light emitter at the end of their abdomen, which is filled with many phosphorus-containing luminescent substances and luminescent enzymes, so that fireflies can emit flashing light. The purpose of fireflies is not only to illuminate, but also to courtship, vigilance, trapping and other purposes.
This is also a communication tool for them. Different kinds of fireflies emit light in different ways, frequencies and colors, so they can convey different messages. 7. Why do you growl when you are hungry? When you are hungry, you will purr. This is because the food you have eaten before is almost digested. Although the stomach is empty, the gastric juice in the stomach will continue to secrete.
At this time, the contraction of the stomach will gradually expand, and the liquid and gas inside will be stirred up, causing a purring sound. Don't feel embarrassed about your stomach growling next time! Because this is a normal physiological action.
8. Why can't ostrich fly? A kind of huge ostrich, but they can't fly to the sky! This is not because their wings are useless, but because their feathers are too soft and their wings are too small to fly at all. In addition, the ostrich's muscles are underdeveloped and its sternum is flat, which is not helpful for flying.
ostriches live in Africa. Because they have lived in desert areas for a long time, their bodies gradually evolved into what they are now in order to adapt to the environment. 9. Why can't canned food go bad easily? Lunch meat, black bean shad, tomato sauce beans.
They are all delicious canned foods, and they can be stored for a long time without spoiling easily.
This is because the can is sealed, so bacteria can't enter. When people make canned food, they pump all the air out of the canned food and then seal it.
in the absence of air, even if the food inside is stained with a little bacteria, they can't survive or reproduce! 1. Why do babies cry all the time when they are born? Babies will cry when they are born, not because they are unhappy, but because they are taking their first breath of air! When babies leave their mother's body and are born, the first breath of air they breathe will rush to their throats, which will violently impact the vocal cords, make them vibrate, and then make a sound similar to crying. 11. Why do lizards keep bouncing when their tails are broken? In order to protect themselves, many lizards also protect their eyes and ears; When some lizards are attacked, their tails will be broken due to the severe contraction of muscles.
Based on the broken tail, some nerves are still alive, and it will keep bouncing, thus distracting the enemy and escaping. Don't think that their lives will end like this. In fact, it only takes a few months, and their tails will grow back and continue to live.
12. Why is the squirrel's tail so big? Don't look at the tail of the relaxed mouse! While the squirrel is jumping around the tree, its tail is playing a great role. It can balance the squirrel when jumping on the tree and avoid falling and being injured.
In addition, this big tail can play a protective role in winter, and it is convenient and practical to tightly surround the squirrel's body. 13. Why can't a person have one or three thumbs? The average person has five fingers, and the length of each finger is different.
However, does anyone realize that besides the thumb, other fingers also have three sections, but only the thumb has two sections? It turns out that its number of joints just matches the other four fingers. If it is three knots, the thumb will appear powerless, so that it can't lift heavy objects; If there is only one section, it can't freely cooperate with the other four fingers to grasp things! 14. Why don't you feel itchy when you scratch yourself? When others scratch ourselves, we will feel itchy and laugh constantly; However, when we scratch ourselves, we not only don't laugh, but also don't feel itchy.
Based on our mental preparation, our brains will send out a message that there is no danger, and our nerves will relax, so we won't laugh and feel itchy! 15. Why is the sea water mostly blue and green? Looking at the sea, I often find that the sea water is blue and green. However, when you pick up the sea water, you can only see it as transparent and colorless as the old water.
It turns out that the seawater itself is not as big as the water we come into contact with every day.
3. What are the scientific common sense in life?
Little common sense in life science--------
Avoid cooking with cold tap water
Many people are used to cooking with cold tap water, which is actually unscientific. Because raw and cold tap water contains a certain amount of chlorine, it will destroy vitamin B1 which is indispensable to human body in the process of cooking. According to the measurement, when cooking with tap water, the loss of vitamin B1 is directly proportional to the cooking time and temperature, and in general, the loss is about 3%. If you cook with boiled water, vitamin B1 can be saved from loss, because the boiled water and chlorine have evaporated with water vapor.
Don't squeeze water when making dumpling stuffing
In daily life, people often use Chinese cabbage, leeks, celery, pigs and mutton as dumpling stuffing. Because there is a lot of water in vegetables, people are used to squeezing out the water in the stuffing of dumplings to prevent the soup from flowing. This practice is unscientific. Because vegetable water contains a lot of B vitamins and vitamin C, it also contains carotene and minerals needed by the human body. And after squeezing out the soup, the packaged jiaozi tastes dry. Then, how can we not squeeze out the water in the stuffing, and not let the stuffing of dumplings flow? The method is as follows: firstly, chop the meat and onion, add seasoning and mix well, then chop the Chinese cabbage without adding salt, and add the chopped Chinese cabbage into the meat stuffing bit by bit, while stirring, so that the meat stuffing can evenly absorb the water in the vegetable stuffing, and the packaged jiaozi is delicious.
don't eat hot food
some people like to eat very hot and very hot food, and this habit is very harmful .33313333333333333, 3635333, e4b893, e5b19e333336 After investigation, the incidence of esophageal cancer is related to eating hot food and scalding food. The normal temperature of human mouth and esophagus is 36.5~37.2℃, and its heat-resistant temperature is 5~6℃. If the temperature of eating and drinking water is too high, the oral mucosa and esophageal wall will be scalded. People feel very hot and very hot food, usually at 7~8℃. If they eat this food regularly, the mucosa of the oral cavity and esophageal wall will be constantly damaged and new cells will continue to proliferate. If the long-term * * * and sometimes human pathological changes and inflammation accelerate the process of cell regeneration, it is likely to become oral cancer and esophageal cancer. Therefore, it is not advisable to eat hot food.
avoid using painted chopsticks
painted chopsticks are beautiful and cheap, but from the health point of view, they are harmful to health. This is because. Paint is a polymer organic compound, which mostly contains toxic chemical components, especially yellow paint, which is made of yellow pigment containing lead and chromium. The lead content accounts for 64% of the total pigment, and the chromium content also reaches 16.1%. Some green (mixed with blue and yellow) and brown (mixed with yellow, red and black) paints also contain lead and chromium. When eating with painted chopsticks for a long time, especially when the paint falls off and is swallowed with food, toxic substances such as lead and chromium will enter the human body and be accumulated, which will lead to chronic poisoning. The lead poisoning dose is .4g, and the lethal dose is about 2g. The amount of lead entering the body in each mouth exceeds 1 mg, which can cause harm to the human body. Lead mainly damages the nervous system, hematopoietic organs and kidneys. In severe cases, it can cause oral metallic ignorance, lead lines in the gums, gastrointestinal symptoms, neurasthenia and muscle pain. In particular, it will affect children's intellectual development. Therefore, in daily life, it is best not to eat with painted chopsticks, but to choose high-quality bamboo chopsticks or non-toxic wooden or plastic chopsticks that meet the hygiene standards.
4. General knowledge of life science
1. When you eat spicy food, you feel that it will kill you. Just put a little salt in your mouth, hold it, spit it out, and rinse your mouth, so it won't be spicy. ? 2. Yellow teeth, you can chew peanuts and put them in your mouth, and brush your teeth for three minutes, which is very effective; 3. If there is a small area of skin injury or burn or scald, apply a little toothpaste to stop bleeding and relieve pain immediately; ? 4. Always leave ugly tea stains in the cups filled with tea, and wash them with toothpaste, which is very clean; ? 5. Open your mouth slightly when you look up at the eye drops, so that your eyes will not blink; ? 6. If there is an ulcer in the mouth, stick it on the ulcer with vitamin C, and the ulcer will basically be fine after it dissolves; ? 7. Small dust enters your eyes, close your eyes and cough hard a few times, and the dust will come out by itself; ? 8. After washing your face, gently apply some fine salt to both sides of your nose with your fingers, and then rinse with clear water, so that blackheads and acne will be removed and pores will become smaller; ? 9. When you have just been bitten by a mosquito, it won't itch if you apply soap; ? 1. If the throat and gums are inflamed, cut the watermelon into small pieces at night and eat it with salt. Remember that it must be at night, when the symptoms will be alleviated, it will be fine the next day; ? 11. The hair dryer blows at the label, and when the glue of the trademark is hot, the label can be easily torn off; ? 12. If you are afraid of wrinkles when you travel with clothes, you can roll every piece of clothing into a roll; ? 13. Drink vinegar when you are snoring, and you will get immediate results; ? 14. Eat something that smells bad, such as garlic and stinky tofu. Just eat a few peanuts. ? 15. Treat cough, especially dry cough. Before going to bed at night, fry eggs with pure sesame oil, put a little more oil, and don't put any seasonings. Go to bed when it is hot, and even eat for a few days, the effect is obvious; ? 16. MM with long and thick wrists can't wear a thin bracelet. They should put a plastic bag on their hands and wear a bracelet, which is very easy to wear and won't hurt their hands. It's the same way to take it off; ? 17. Chestnut skin is difficult to peel. Peel off the shell first, then turn it in the microwave oven, take it out and rub it while it is hot, and the skin will fall off; ? 18. When arranging flowers, drop a drop of detergent in the water for several days; ? 19. Put the walnut in the pot and steam it for ten minutes, then take it out and put it in cold water and open it, and you can take out the complete peach kernel; ? 2. Put the shrimps in a bowl, add a little salt and edible alkali powder, rub them with your hands for a while, then soak them in clear water, and then rinse them with clear water, which will make the fried shrimps transparent as crystal, refreshing and delicious; ? 21. When frying meat, first soak the meat in baking soda water for ten minutes, pour out the water, and then taste it. It will be tender and smooth when fried; ? 22. Soak the residual tea leaves in water for several days, and then pour them on the roots of plants, which can promote the growth of plants; ? 23. Dry the residual tea leaves and smoke them in the toilet or ditch, which can eliminate the stench and have the function of expelling mosquitoes and flies; ? 24. uncooked rice re-cooking method: you can use chopsticks to tie some holes in the rice that go straight to the bottom of the pot, sprinkle a little yellow wine and re-stew. 25. If only the surface is sandwiched, just turn the surface to the middle and then simmer; ? 26. Ingeniously remove the greasy screen window: put the cigarette butts left after washing clothes and smoking in the water together, and use them to clean the glass windows and screens after being dissolved. The effect is really good; ? 27. As long as you put a small piece of chalk in the jewelry box, you can keep the jewelry shiny; ? 28. Self-adhesive traces on the surface of tables and bottles can be wiped with wind oil essence; ? 29. Take a small dry battery in your bag at any time when you go out. If the skirt is charged with static electricity, wipe the positive electrode of the battery on the skirt a few times to remove static electricity; ? 3. No matter where the shoes rub your feet, you should apply a little white wine to the place where the shoes rub your feet to ensure that you don't rub your feet. ? 31. When mixing vegetables, if you have to blanch them, you'd better make the best use of the water for cooking them.
For cooking dumplings, the boiled water can be put in the meat stuffing in a proper amount, which not only ensures the nutrition, but also makes the dumpling stuffing delicious and soup. ? 32. In summer, feet are prone to sweating. Soaking feet with light salt water every day can effectively deal with sweaty feet; ? 33. Sunbathing after swimming in summer can prevent diseases such as skin strain; ? 34. Summer