Under the combined effects of atmospheric qiang element and yi element, a phenomenon emerged during the overall evolution of Earth's organisms that remains unexplained to this day: the lower the organism, the higher its degree of evolution.
While humans generally experienced a twofold evolution, with a multi-evolution rate of about two-thousandths, many simple-structured invertebrates commonly underwent an eightfold evolution, and their multi-evolution rate was significantly higher than that of humans.
Therefore, after the catastrophe, the organisms on the Blue Star were several times more dangerous to humans than before the catastrophe.
While the Evolved Organisms of the Blue Star posed a threat to human life, they also brought a chance for survival: organisms containing trace amounts of harmful radioactive elements and qiang element, neither exceeding five-thousandths.
Researchers named them: Safe Food.
Currently, research has confirmed three points: first, the lower the content of these two types of elements, the more beneficial they are to the human body; second, the higher the proportion of Safe Food in one's diet, the stronger humanity's ability to resist environmental pollution; and third, multi-evolved Safe Organisms are significantly more effective at enhancing human immunity than ordinary Safe Food.
Since Safe Food could not meet the dietary needs of the entire nation, Huaguo designated edible organisms containing trace amounts or no harmful radioactive elements, and with a qiang element content between five-thousandths and fifteen-thousandths, as Optional Food.
When Safe Food and Optional Food were tested with a common qiang element detector, both showed a green light.
The Evolved Catfish Xia Qing killed, if taken to the Safe Zone, could be exchanged for enough rations to last her three months.
However, Xia Qing, having eaten enough coarse compressed composite rations, now only wanted to eat meat.
She quickly cleaned the catfish, chopped a few pieces, threw them into the pot, added mountain water, and started cooking.
Seasonings? Only salt and chili powder.
Side dishes? None.
No, she had Evolved Potato seeds, six catties.
But Xia Qing was reluctant to eat them, because the planting encyclopedia clearly stated that these were potato seeds with a harmful element content of only 7.5 thousandths, and their germination rate was very low, between 30% and 35%.
The six catties of potatoes she had obtained, how many seedlings they would yield, and how many catties of potatoes she would harvest, were all unknown, so she was reluctant to eat them.
Soon, an alluring meaty aroma wafted from the pot. Xia Qing sniffed, confirming that her stewed catfish smelled even better than the stewed fish sold in the Safe Zone canteen, and had less of a muddy smell.
This catfish was very likely Safe Food.
Although her appetite had doubled after evolution, Xia Qing could not finish this ten-plus catty catfish in one meal.
There was no way to preserve fresh food in the territory, so Xia Qing slowly roasted the unfinished fish into dried fish, then sealed it in bags for preservation.
Only this way would the fish meat not be corroded and spoil by the qiang element and Evolved Fungi in the air.
In the future, she would have more and more food, so she had to find a way to get solar panels and a refrigerator as soon as possible. But before that, she had to find glass to fix the windows to fend off attacks from Evolved Insects or snakes, insects, rats, and ants.
Xia Qing picked up her large canvas bag and tools, deciding to use the afternoon to patrol Huang Village.
Within the Third Land, there were three villages arranged in a triangular shape, with their locations slightly higher than the cultivated land, separated by large expanses of farmland. Each village had dozens of households before the catastrophe, and now only dozens of house ruins remained.
Xia Qing lived in the Huang Village at the top of the triangle, with one Huang Village to its southeast and another to its southwest.
The houses in Huang Village had long been swallowed by plants. Xia Qing pushed aside the weeds and saw many gnawed-clean human and animal bones.
Xia Qing had seen such scenes countless times over the past decade and had long since become numb to them.
After searching the three villages, Xia Qing found tempered laminated glass of suitable size, cleaned it, and installed it in her window frames according to her home's window dimensions, firmly securing it with glass glue and special sealing strips.
By the tenth year, building materials produced before the catastrophe had long passed their expiration date and were unusable. The materials she was using now were brought from the Safe Zone, produced after the catastrophe.
The catastrophe destroyed the Blue Star's original industrial production system, causing most supplies that could be easily bought by pressing a phone button before the catastrophe to become scarce goods that couldn't be found anywhere.
Even this glass glue and sealing strips were obtained by Xia Qing by virtue of her position as a small team leader in the construction team.
After her father's death, Xia Qing, being orphaned and beautiful, wanted to live comfortably and decently in the Safe Zone. She either needed extraordinary strength, or to live with a group of powerful teammates she could rely on, or to sell herself for daily necessities.
Xia Qing had no extraordinary strength, no trustworthy teammates, and even less desired to sell her body, so she chose to cut her long hair, smear her face red, and join the construction team to do manual labor.
Earning points was a secondary goal; Xia Qing's main purpose was to hide herself, learn construction techniques, and accumulate materials and tools that could not be bought on the market, preparing for living alone after leaving the Safe Zone.
Of course, there were also people in the construction team who had designs on Xia Qing, but after experiencing her formidable strength, they all abandoned their ulterior motives.
For those who refused to give up, if they could be killed, Xia Qing directly took their lives; if they couldn't be killed, Xia Qing could only avoid them, using underhanded tactics to make them too busy to notice her dirty appearance.
After installing the bright glass, Xia Qing let out a long sigh of relief. Her home was finally secure.
While there was still some time before dark, Xia Qing took a shovel to the neighboring yard and dug a pit to bury the two human skeletons, one large and one small, and a dog, all covered by weeds.
These two people and one dog were killed by the Evolved Plant Mistletoe. From their posture, the dog was trying to save its owner until its death.
The seeds of Evolved Mistletoe could not only parasitize tree trunks but also animals and human bodies. If the host did not detect and thoroughly remove it in time, they would soon be drained of blood and flesh and die.
Xia Qing still remembered seeing the strings of bright red Mistletoe fruits growing on the bodies of people killed by Mistletoe for the first time. At that time, she thought it was the most terrifying scene of the catastrophe.
But in these subsequent years, one dangerous encounter after another taught her that there was no 'most terrifying,' only 'more terrifying.' Fortunately, humans now had protective suits and other self-protection methods, so as long as they did not rashly enter uncleared Evolution Forests, they would not suffer large-scale attacks from Evolved Organisms.
After burying this family of three, Xia Qing also tidied up the weeds and house in the yard.
This family was in the process of building a house; the two-story main structure, cast with reinforced concrete, had just been completed when it encountered acid rain and the great biological evolution. So, the secondary structure, doors, and windows of the house had not yet been done, and the purchased building materials were piled up in the rooms on the second floor.
Fortunately, the roof used resin tiles, and the homeowner had done their best to protect the house, otherwise, after half a year of heavy acid rain, not to mention concrete, even the rebar would have been dissolved.
Xia Qing was alone, and the current two-story small building was enough for her to live in, so she decided to clear out this framed building and use it as a storeroom to store some large and less important materials, such as farm tools, building materials, old furniture, and wood.
After tidying up and taking another look around, Xia Qing felt a sense of accomplishment, but also felt that she should quickly raise an Evolved Animal that could guard the house, preferably an intelligent one.
Evolved Dog and goose were both fine, preferably a goose, because it was a vegetarian. Xia Qing herself didn't have meat to eat, so she couldn't afford a dog.
However, this was just a thought; an animal that could still be tamed by humans after evolution was hard to find. Xia Qing did not think she would be lucky enough to wait and find one in her territory.
At this stage, planting the land was the most important thing.