After the two returned to the shelter, Cheng Ran smashed the charcoal into a stone to the size of a grain of sand, and Cheng Ran was ready to make a filter device.

First of all, I spread the sand under the water tank once, then spread the charcoal once, then spread the sand again, and then spread it layer by layer, until there is almost ten centimeters at the top of the tank, and then press it with my hands, and finally lay a layer of small gravel, and this is basically done.

Even if a filtration device is done, all that remains is to make a base, and Cheng Ran can't hold it with his hands all the time.

Cheng Ran thought of a simple and most convenient way, which was to use three relatively thick wooden sticks and then tie them together with rattan and tie them to a third of the place.

I opened the three sticks tied together to make a simple tripod, tested it with a water tank, adjusted it a few times according to the size, and then fixed the long end of the tripod to the ground, and then stopped after throwing stones into the dirt to look like about ten centimeters, and found some large stones to press around the three sticks.

After making the whole set of water filtration devices, Cheng Ran plans to let the water settle in the water tank overnight, and then filter it, so that the water should be clearer.

The problem of water is solved, and now the problem is to eat.

Now that it was getting dark, Li Yuxin had already cooked the rice, Cheng Ran simply felt that today was the only way to go, and when the two of them were eating, they found that although they had bowls but did not make chopsticks, they had no choice but to fold a few branches to serve as chopsticks.

At this time, Li Yuxin suddenly said: "I think it's a little inconvenient to drink water without a teapot, and every time I drink water, there is a freshly boiled water." ”

"Let's go inside tomorrow first, and when I come back, I'll make a few more pieces," Cheng Ran said after thinking for a while

"I'll do it myself, although I can't share many things for you, but these little things, I will try to share as much as I can, and I can't put everything on you." Li Yuxin said solemnly

"Then you should pay attention to safety when firing, and suddenly think that this is not bad." Cheng Ran said jokingly

"What do you think is good?" Li Yuxin blushed and looked at Cheng Ran embarrassedly and asked

"I used to think that I could have my own house, and when I came home from working outside the home, I had someone I liked and a hot meal, which was already my biggest wish." Cheng Ran recalled and said

"Then you must have a girlfriend." Li Yuxin asked with a little disappointment

"Not now, tell me about your boyfriend." Cheng Ran said a little sadly

"I haven't talked about it yet, I didn't talk about it when I was in school, and I didn't have time when I was working," Li Yuxin said with some surprise and shyness in her heart

"No, a beauty like you, no one will chase you," Cheng Ran asked in surprise

"There were a few, but I was still in school at the time, so I didn't agree, and when I was working, I didn't talk about it." Li Yuxin said

At this time, the sky began to fall, and the two of them walked into the shelter, and at this time, they had no choice but to sleep separately without the atmosphere they had just had.

The next morning, Cheng Ran, who was full of food and drink, walked along the seaside to the east, the beach is very easy to walk, much easier to walk than the jungle, about 20 minutes to walk, and then walked to the edge of the cliff.

Cheng Ran carefully observed this cliff, the seaside by which he leaned was basically vertical, and it was impossible to go up from the seaside.

Cheng Ranzhi walked along the edge of the cliff to the forest, and when he walked into the forest, the road was not easy to walk, either the stones blocked the way or the jungle was too dense, and there was no machete.

While walking along the ridge, Cheng Ran also thought that it was best to climb to the top of the mountain and climb to the highest point of this island, so that the whole picture of this island could be seen at a glance, and he could see more intuitively that there was no one on this island.

Cheng Ran kept trying a few times and found that he couldn't go up from this side at all, either a lot of big rocks or cliffs blocked the road.

Along the way, Cheng Ran didn't find anything he thought was useful, there were useless places here, and there was no need to come here in the future.

When Cheng Ran walked back for only ten minutes, he saw a few trees, and was pleasantly surprised by the fruits that bore on them.

In the past few days, the two of them have eaten all the fruits of the fruit trees they found before, and they can no longer find any more fruits that can be eaten.

Walking quickly to the fruit tree, Cheng Ran was surprised to find that he knew this fruit tree, the mango tree!! Looks like it's a tropical island

Cheng Ran found many fallen ripe mangoes on the ground, Cheng Ran immediately took off his T-shirt, and then picked up all the mangoes.

Cheng Ran was very happy along the way, he didn't have to eat bananas and the unknown fruit anymore, he planned to change his taste and eat mango today, and he didn't eat anything else, and he didn't get anything other valuable along the way, so he returned to the shelter non-stop.

put down the mango and Li Yuxin said, "Let's change the taste today."

"If we don't eat these things, then what do we eat?" Li Yuxin, who was making pottery, said without raising her head

"Eat you," Cheng Ran said jokingly with a smile

"You're kidding." Li Yuxin said in a little panic

"When I came back, I saw a few mango trees, and there were mangoes to eat today." Cheng Ran said a little disappointed

"Really, I don't want to eat bananas anymore." Li Yuxin said disappointedly.

After looking at the water in the water tank and finding that it was much clearer than when he first came back, Cheng Ran put the device for filtering water on the tripod he had made before, and put another water tank under the tripod to start filtering water.

Using a bowl to pump water into the filter, Cheng Ran waited for a while before finding that the inside of the gap began to drip down drop by drop.

Judging from the dripping water, Cheng Ran didn't find any difference from before it was not filtered, and after waiting for a while, he took two bowls of water and tried the difference between the two buckets of water, and found that the two buckets of water were almost the same clear, and he could only see that there were some small dots similar to plankton in the unfiltered bucket of water, which seemed very unhygienic, but after filtering, it was different.

At this time, it was getting late, Cheng Ran and Li Yuxin sat on the fire eating mangoes and drinking shell soup, while going over from time to time to add some water to the filter.

After eating the mango, the shell soup was also cooked at this time, and when Cheng Ran was about to drink it, he found that there was no place to start, and he couldn't pick it up at all, it was too hot to have a soup spoon, helplessly, the two of them could only wait for the shell soup to cool down before drinking.

Now that food, water, shelter and fire are complete, Cheng Ran has already met the four basic conditions for survival, and the worst condition is the shelter.