The mystery of missing tin cans

Tao Tao is a little bear. He is both naughty and bold.

One day, Tao Tao was foraging in the forest, walking and walking, and unconsciously came to the cabin of the ranger Lao Wang.

Lao Wang is no stranger to Tao Tao. When Tao Tao was very young, Lao Wang often put the fish caught from the river bank for Tao Tao to eat. When Tao Tao is full of food and drink, he often rolls and somersaults to relieve boredom. Over time, Tao Tao and Lao Wang became good friends.

At this time, Lao Wang is pouring drinks for himself in the forest protection room. Seeing Tao Tao coming, Lao Wang picked up an apple and handed it to Tao Tao. Tao Tao took the apple, squatted on the ground and ate it sweetly.

Tao Tao ate and watched Lao Wang drink.

When Lao Wang picked up the hip flask and poured it into the glass, the hip flask in Lao Wang's hand caught Tao Tao's attention.

"What is this?" Tao Tao looked at the hip flask curiously and thought, "The contents must be delicious, otherwise, he wouldn't just take a sip at a time."

This is a tin hip flask, which was specially made by Lao Wang's son for the convenience of his father.

After Tao Tao finished eating the apples, Lao Wang stopped drinking. He stood up and said to Tao Tao, "Come on, I'll fish for you!" "

Lao Wang picked up the fishing rod and walked to the river. Tao Tao glanced at the hip flask again, and then followed Lao Wang out of the door.

Tao Tao kept thinking about the hip flask. He ate some fish, thanked Lao Wang without somersaulting, and left in a hurry.

Although Lao Wang is puzzled by Tao Tao's abnormal behavior, it is understandable that Tao Tao is a wild animal after all and has some abnormal behaviors.

Lao Wang continued to fish by the river.

two

Tao Tao came to the forest protection room, picked up Lao Wang's hip flask and ran away.

After running to a secluded place, Tao Tao sniffed the mouth of the hip flask and squinted and said, "Wow, it smells good!" "

Tao Tao tried to drink some more. It's a little spicy, but it tastes great.

Tao Tao doesn't want to drink all the wine in the hip flask in one day. He only takes a sip every day. However, there is too little wine in the hip flask. A few days later, Tao Tao finished drinking.

In the later days, whenever Tao Tao wanted to drink, he had to smell the hip flask.

Unconsciously, winter has arrived. Tao Tao, it's time to hibernate.

Tao Tao didn't want to give up the aroma of the hip flask, but it was inconvenient to bring it into the tree hole.

"What should I do?" After careful consideration, Tao Tao finally hid the hip flask in a crack in a rock.

When the birds in the forest woke Tao Tao from his sleep, it was already spring. Tao Tao climbed out of the tree hole, stretched himself and found something to eat. At this time, a strong fragrance of flowers came to my face. Facing the direction of flowers, Tao Tao saw clumps of shepherd's purse flowers swaying in the wind.

The fragrance of flowers reminds Tao Tao of the smell of wine.

Tao Tao hurried to the crack of the hidden hip flask.

Before he came to the crack, Tao Tao looked for it, but he couldn't find a hip flask that smelled of wine.

"Someone must have stolen my hip flask!"

Thinking of this, Tao Tao unconsciously shouted: "Whoever stole my hip flask, bring it back to me quickly!" "

Tao Tao's cry attracted many friends who lived in the mountains.

The deer asked with concern, "Did you remember the wrong place?"

Tao Tao said, "No, I remember it very clearly!" "

Lamb said: "Our mountain forest has always been a road without picking up the remains, and it is not closed at night. How can something be missing? "

The fox said, "It's just a broken hip flask. Who needs to steal this! " "

……

Just as friends were talking about it, a well-informed parrot lady flew over.

Miss parrot asked what was going on, flew to the crack of the stone where Little Bear hid the hip flask, and then pointed to a pile of gray powder in the crack of the stone and said, "Look, where is your hip flask!" " "

three

"How is that possible? How can this be my hip flask? " Bell doesn't believe that the present situation is true.

Miss parrot said, "Your hip flask is probably made of tin?"

The bear shook his head and said, "I don't know."

Miss parrot said, "Where did you get your hip flask?"

Bear shyly told Miss Parrot the origin of the hip flask, and then said, "I originally wanted to give it back to Lao Wang when the fragrance in the hip flask was gone. What's the use of asking for a hip flask! "

"That's right!" Miss parrot said, "Don't take other people's things casually in the future!" " "

Bell nodded in agreement. Then he asked, "How did the hip flask turn into a pile of ashes?"

Miss parrot said, "you may not know that tin has a strange property." It is very sensitive to cold, and it will get sick when it is cold. " . At this time, it gradually changes from white to gray, the volume gradually increases, and at the same time, it cracks and often breaks into powder. At MINUS 30 degrees, the speed of this change will be greatly accelerated. "

"Oh, so that's it!" The bear said, "It's a pity to have a good hip flask!" "

Miss parrot went on to say, "Pure tin is a soft and weak metal, which is not conducive to manufacturing supplies." However, by adding 10% tin to copper, a golden alloy-'bronze' is made, which is superior in texture, harder than pure copper, and easy to cast, forge and process. If we set the hardness of tin to 5, then the hardness of copper is 30, and the hardness of bronze, an alloy composed of copper and a small amount of tin, is 100- 150. These properties of bronze made it widely used by human beings for a period of time, and archaeologists even drew a special historical era called the Bronze Age. "

"Wow, you know so much!" All the friends in the mountain forest said with one voice.

Miss parrot said, "Since the mystery of the missing hip flask is clear, let's go to our own activities!" " "

Shanyou went to his favorite place to find food.

The bear walked sadly to the forest protection room.

Knowledge Link: Tin also has many unique properties. For example, tin will "cry", that is, when a tin bar or tin plate is bent, it will make a special cracking sound that seems to cry. People call this phenomenon "tin barking", and this kind of tin is called "ringing tin". This is because white tin crystals rub against each other when bending and make a sound. When lead is mixed in tin, the sound will be lowered.