The trio searched for an exit along the shore of Lake Yushen, and after about four hours of walking, a stream of water began to fork into several tributaries. Tianxuan looked into the distance and found that the color of the river gradually changed from light to dark, and some tributaries even appeared red and yellow.

"Nicos, why is there red and yellow water in this divide?" Tianxuan asked.

"It's the same crude oil as the water in Lake Yushen I've seen before." Nicos gently flicked her hairline and continued, "The color of crude oil is related to the amount of non-hydrocarbon substances contained in it, the higher the content, the darker the color, and the purest crude oil is pure hydrocarbons. ”

Tianxuan touched his cheek with his hand, his eyebrows slightly slanted and asked curiously, "What substances are mixed in the red crude oil and the yellow crude oil?" ”

Nicolas circled his finger in the air and said, "The red crude oil has a lot of lead in it, and the yellow crude oil has a lot of sulfide in it. In the end, the crude oil with the most impurities appears as a black, viscous substance. ”

After listening to Nicos's words, Tianxuan realized that the oil usually used on the ground is the most inferior variety, but there is a river of crude oil here, and in a sense, the crude oil resources here are as cheap as water.

"Wow! So you have a lot of oil here, and there is no shortage of transportation energy at all? Tianxuan's eyes lit up and exclaimed.

"What are you kidding? Crude oil is used as an energy source that produces a lot of pollution and waste, and we prohibit the use of energy here! Nicos said with a serious face.

Hearing this, Tianxuan was taken aback, and thought to himself: "The Mayans are really tyrannical! On the ground, there is a fight for oil and life, and here it is not taken seriously at all, and it is regarded as grass mustard. ”

In this way, the two of them chatted while walking along the shore, and after a while, the crude oil river in the distance really appeared black.

"It seems that this is the crude oil with the most impurities." Tianxuan's arm was half-blocked in front of Nicoth, pointing to the black river in the distance.

"Hmmm! Indeed it is! Nicolas blinked calmly at Tianxuan, nodded and said.

Since it was determined that he would arrive at the river of crude oil with the worst purity soon after, but still did not see the refinery, Tianxuan was puzzled: "Where is the Nicols Refinery?" It stands to reason that it is generally located in the location with the best raw materials! I didn't see a shadow when I got to the Black River. ”

Nicols's eyebrows curled up slightly, and the corners of his mouth curled up again and said with a smile: "Don't worry, the location of the refining factory is the place with the most variety, which is convenient for refining various substances and products." And your definition is too arbitrary, the purest crude oil is the best raw material, this doesn't make sense, the key is to see how you use the material where it should be. ”

After listening to Nicos's education, Tianxuan shrugged his head and lowered his head in thought: he was ashamed of his concept of wasting resources. After careful reflection, I suddenly understood: some waste cooking oil was used by some unscrupulous businessmen on the table to earn a little gross profit, while some scientists used refining machines to produce various chemical products to make a fortune, this is the gap!

Thinking of this, Tianxuan couldn't help but shake his head and sigh, feeling contempt for his backward thoughts.

Tianxuan continued to move forward with thoughts, and the other two did not disturb his artistic conception. After they walked along the shore for a while, Tianxuan looked up sharply and found that the corpses of some plants and animals began to float on the crude oil river, and he thought it was strange.

"Huh? Now the river here seems to have buoyancy to float something. Tianxuan felt a little unbelievable that there were animals or plants so light, and after thinking about it, he said to himself, "Could it be that they don't have any bones?" ”

Hercules, looking at Tianxuan, raised his eyes and glanced at him, then shook his head like a rattle.

Nicos came to Tianxuan's side at this time, tapped his forehead mischievously with his fingers and said, "That's not the case! There was no problem with the animals at all. It's the density of crude oil that has changed! ”

"How?" Tianxuan asked.

Nicos took out a fist-sized square container from his backpack and drew a circle in front of Tianxuan, then held it to his chest and said: "For example, taking the ordinary water we drink as a reference, assuming that this container is 1 cubic meter, and then the ratio of the mass to volume of water in this container is regarded as 1, then the ratio of crude oil to water is generally between 0.75~0.95, and the ratio of Yushen Lake is far less than 0.75. Now you know!"

"Yes, yes! This is what I learned, which is the buoyancy principle discovered by Archimedes. Tianxuan suddenly understood, and hurriedly stretched out his right index finger and middle finger and shook it to show understanding, "Buoyancy is the gravity of discharging liquid when an object sinks. In other words, after the container is filled with crude oil from the lake, the ratio of the object to the water can be measured by the volume discharged. That's why the feathers sink! ”

"Yes, that's right!" At this time, Nicos stretched out his right hand to hide his face and smiled, not because he was ignorant, but because he thought Tianxuan's way of speaking was quite funny.

It was at this moment that Hercules discovered something: "Look, there's a strong light ahead, what is that?" ”

Nikos took a few deep breaths and stopped laughing, looking in the direction Hercules was pointing.

"We'll be at one of the refineries soon!" Nicols's cheeks bulged slightly, her eyebrows curved up sharply, her pupils suddenly dilated, and her eyes were filled with infinite excitement.

The three of them walked towards the light, and as they got closer, Tianxuan looked at the so-called refinery, a complex of buildings built on at least a hundred small islands in the center of the lake—these buildings looked like a circular city from a distance.

Curious, Tianxuan continued to take a closer look, but in fact, these circular buildings were not a whole. The river divides the circular factory into dried tofu pieces from below, and these tofu blocks are connected by bridges or rails, which is a living water city.

The three of them then walked to the edge of a bridge that connected to the shore, when a pungent smell wafted from the water, which was like oil anyway, but mixed with some more unpleasant gases. Just as Tengen and Hercules were covering their mouths and noses to get on the bridge, Nicos stretched out her arms against their chests and motioned for them to stop.

"What's going on here, Nicos?" Tianxuan asked with an eyebrow squeezed.

I saw Nicos blink, then walked to the purple stone pillar next to the bridge, drew some alchemist symbols, and then the three-meter-wide bridge instantly covered an almost transparent protective shield.

"It's time to get on the bridge!" Nicos raised her head and pouted, and said very confidently.

This book was first published in Reading Book Worm