"Yao Jue has already fallen asleep, you don't have to worry, take care of your body. If you're hungry, I'll grill fish for you. After saying that, Feng Yuyu got up and picked up the fish that was placed on the pyre.

Li Pian'er looked puzzled and asked, "Where did you find it on such a cold day?" You can't be in the canal again, right? Are you crazy? You're going to get sick like that. Besides, last night's situation was different from today's, and if it wasn't for their lives, who would want to get into the water so cold. ”

Feng Yuyu saw that Li Pian'er was nervous because of his matter, and finally had a trace of warmth in her heart. He stuck a branch into the belly of the fish and set it on the fire and roasted it. Since he didn't have the tools to handle the fish's internal organs, he had to bake them directly, which was better than starving. There is still a long way to go, and you have to save the baked cakes in your bag.

"You don't have to be nervous, I'm not close to the canal. This fish was found in the river in front of the forest, it was dead at the time, I just picked it up, you don't have meat now, the child in the belly needs nutrition. Feng Yuyu said as she added some firewood to the fire, and then returned to Li Pian'er with the pile of roots on the ground.

Li Pian'er moved, her faint gaze stayed on the seven or eight roots, and asked puzzledly, "What is this?" ”

"Peony flower root, it should be edible. Fang found the dead branches left by it by the river, so he started digging down, and it was not in vain. The dirt on the roots had been washed in the river, and he picked up a piece and looked at it for a moment, then tried to bite it. It's not delicious, but it's not unpleasant, and the taste is light and crisp, with a raw flavor. He didn't plan to give Li Pian'er to eat this, this was what he prepared for himself in order to save more dry food, and he would never bear to let Li Pian'er eat this kind of thing.

Li Pian'er watched Feng Yuyu eat four pieces in a row, and hurriedly stopped: "You won't be ready to eat this tonight, right?" Don't eat it, I don't even know if it's poisonous, you still eat so much, be careful of eating your body, let's eat fish together later. ”

"Don't worry, this one is non-toxic, as long as it fills your stomach. By the way, Lianlian, how did you know that the bottom of the water is warmer than the surface of the water? Is it because of the reason for surfing? Feng Yuyu thought of what happened last night, and couldn't help but ask the doubts in her heart.

The smell of grilled fish diffused in the air, and Li Pian'er took a breath unconsciously, then shook her head and said, "This has nothing to do with my surfing." This was just the knowledge I learned in physics class at that time, but I didn't expect it to save our lives, I knew that I should have studied hard at that time, but unfortunately, now I know so much. ”

Thinking of this, Li Pian'er looked annoyed, paused, and said: "In fact, the reason is very simple, the density of water will change with the change of temperature, and when the water temperature reaches four degrees Celsius, the density will reach the maximum value, so it will sink, so the water temperature of each layer is different." The canal is quite deep, and I think the water temperature at the bottom of the river must be four degrees Celsius, which is much warmer than the outside. In fact, if you look at it, you will find that there are often fish swimming under the frozen lake. If it weren't for this, the fish would have frozen to death long ago. ”

"There is such a miraculous thing, I have never thought about the question of why there are live fish swimming in the ice lake. Will all the students of the future world learn this? It's fun, and it's life-saving at critical moments. Feng Yuxuan only understood Li Pian'er's explanation, and the word "density" was still too novel for him to understand what "density" was.

Li Pian'er leaned on a wooden board and nodded her head quietly: "There are still a lot of useful ones, but I don't know how to learn, and most of them sleep during class." Also, last night we were frozen in wet clothes for half the night, and we didn't die, in fact, there is a reason for this. Liquids release heat when they turn into solids, and although our wet clothes eventually harden, they also greatly reduce the heat loss in our bodies. ”