Cold knowledge that many people don't know!

(The following contents and pictures are taken from Baidu)

Let's popularize what cold knowledge is first ~

Cold knowledge refers to those biased, trivial and complicated knowledge and things. This knowledge seems strange or interesting, but it has always been around our lives, but few people pay attention to it. Cold knowledge can increase people's knowledge, broaden people's horizons, enlighten people's thinking and stimulate people's strong thirst for knowledge. Like "cold jokes", cold knowledge is unpopular but useful and more attractive.

Cold knowledge is also called "stupid question"?

All right, cut to the chase.

1, changjin deer can't cough.

Giraffes not only have tapes, but also bark. So, why don't they bark? This is because giraffes have special vocal cords. There is a shallow groove in the middle of its vocal cords, which is not easy to make sound; Moreover, vocalization needs the help of lungs, chest and diaphragm, but because the giraffe's neck is too long and the distance between these organs is too far, it takes a lot of effort to make a sound. So I seldom scream at ordinary times. But sometimes, when the giraffe can't find its mother, it will make a "Cleisthenes moo", just like a calf. The grown giraffe is not only tall, but also sees far. It runs fast, too When it finds an enemy in the distance, it can hide. If it can't hide, it will use a big hoof like a hammer to deal with the enemy, and there is no need to call for help.

1. Because its neck is getting longer and longer, its vibrating organs (vocal cords) and dynamic organs (lungs, chest and diaphragm) are too far away, so it is difficult to make sound.

2. Its vocal cords are gradually degenerating, which is different from normal human vocal cords. Giraffe's vocal cords are small and thick, and there is a longitudinal shallow groove about 25 mm in the center. Such vocal cords themselves are abnormal.

The whale's heartbeat is only 9 times per minute.

Because whales used to be animals on land, and later they lived in water.

Since you have to hold your breath in the water for such a long time, you naturally need to slow down your heartbeat.

Blood carries oxygen. Every time the heart beats, blood circulates in the blood vessels.

If the heart beats faster, the demand for oxygen will increase. If the demand for oxygen is large, the number of times it floats on the water will increase, and the chance of being attacked by natural enemies will also increase greatly.

Everything is for survival, the so-called survival of the fittest.

On the contrary, the heartbeat of hummingbirds can reach 500 times per minute, and the number of flapping wings is 15 to 80 times per second. The reason why its heart beats so fast is that it needs a lot of oxygen to convert it into energy and drive its chest muscles to flap its wings. Oxygen comes from blood vessels, and blood circulation depends on the beating of the heart.

Chocolate contains a chemical called phenyl, which is the same as what you can make in your brain when you are in love.

So chocolate can be aphrodisiac. Chocolate contains a unique Anandamide ingredient, which can quickly excite the nerves that produce good reactions in the human body. This reaction not only has no side effects, but also can last for a long time. Eating chocolate regularly is very helpful for depression, neurasthenia and unhappiness, and it can also eliminate fatigue and refresh the mind.

According to incomplete statistics, only about 30% people will enlarge and narrow their nostrils.

In fact, this is determined by genes ~ just like some people can make their ears move (move their ears)

5. The sex of oyster will change from male to female, and then it will change several times in its life.

The mollusk oyster, commonly known as oyster, is not only rich in nutrition, but also a transsexual expert in the animal kingdom. The sex of oysters is the same year after year, alternating between male and female, changing year after year, and going on for a lifetime.

Oysters come in two genders. When the metabolism of protein in the body is vigorous, the female period is dominant. When carbohydrate metabolism, especially glycogen metabolism, is vigorous in the body, the male phase is dominant.

Some scholars believe that nutritional conditions are not the factors that determine the sex of oysters, but the phenomenon of male precooking. Ostrich, for example, are all males when they are young, even in the case of excellent nutritional conditions. This is because the gonads of young oysters are bisexual, and the sex is often changeable. But in general, due to the rapid formation of sperm, they often appear male at the first sexual maturity and return to bisexual state after the breeding season. What kind of traits are displayed in the second year is determined by nutritional conditions. When the nutritional conditions are superior, oysters grow big and fat, which stimulates the formation and growth of oogonia and inhibits the formation of spermatogonia, resulting in an increase in the proportion of female oysters.

Some scholars have found that there are often bean crabs living in the coat cavity of oysters, and the number of male oysters living in bean crabs has increased significantly, which shows that hermit crabs are related to sexual change.

By the way, oysters are very effective! Can be beautiful ~)

Update here today … Thank you for your attention ~