Every night, the torrential rain makes the Zombie Tide even more terrifying. Now it has been dark for several consecutive nights, and with the rainfall now, the Zombie Tide is bound to occur, so they were not notified to come. Everyone dropped what they were doing and gathered here to check the situation. "Xiao Hang." Li Yu spotted Li Hang’s figure among the crowd. Upon hearing his brother call for him, Li Hang shifted his gaze away from the zombies and stepped out of the crowd. "Brother, I’m here, what’s up?" Li Yu looked at the middle part of the wall, where the Mobile Switch Blade had been installed following He Bing’s suggestion and everyone’s combined efforts. It was currently in a retracted state, sticking to the wall, and the sound of the rain hitting it was a constant clatter. "Go call He Bing over, and both of you go open the Mobile Switch Blade at the bottom of the gate to check if it can function normally." The Mobile Switch Blade had been installed for some time now, but there had never been an opportunity to use it. Previously, the weather was hot, and there were hardly any zombies outside, so it was scarcely needed. Also, the zombies that did appear were never enough to pile up and pose a threat, so it had never been used. Now, there might be a chance to use it. Li Hang looked at the zombies beneath the wall and said excitedly, "Okay, I’ll go call him now." The invention of the Mobile Switch Blade by Li Hang and He Bing required a great deal of effort and dedication. Including its stability, the need for power, the routing of wires, and in order to install this Mobile Switch Blade, they had even extended the width of the wall by half a meter to protect the wiring. After all the effort they had put into it, now that they could finally use it, naturally they wanted to see its effectiveness. Watching Li Hang go down, Li Yu was deeply concerned. With acid rain now falling, the duty roster would definitely need to be rearranged. Base defense would have to be increased once more, and the personnel on the wall would need to be doubled. Moreover, this bout of acid rain was going to last a long time. It would greatly pollute the water supply, even affecting the groundwater that, despite being filtered by thick layers of soil, would still be contaminated due to the prolonged acid rain. Whether the water contaminated by acid rain is drinkable or not. If it were up to pre-apocalyptic experts, it would be undrinkable. But in times of crisis, they would have no choice but to drink it. Mountains, wetlands, rivers, lakes, all would be polluted by acid rain, as would the groundwater. Without water, they would die of thirst. Some places’ water was not so severely polluted by acid rain, and the effects were not too serious. But in some areas, the consequences of drinking water severely polluted by acid rain could be dire. Furthermore, living in acid rain for a long period and drinking acidic water can cause a series of diseases, including respiratory organ damage, kidney diseases, and cancer. The closer you are to the volcanic eruption site, the lower the pH value of the acid rain, the stronger the acidity, and the greater the harm. In acid rain, even if you do not drink it, long-term exposure without protection can be harmful. Initially, acid rain can damage the skin, the acidic substances can affect the lungs’ respiratory function, causing acute and chronic respiratory damage, and also harm the eyes. Acid rain is a disaster, a disaster for humanity. Yet under this acid rain, it is a feast for the zombies. Endless darkness and torrential acid rain, these belong to the zombies’ time to hunt. He Bing and Li Hang ran up the wall, and Li Yu, upon seeing He Bing without his protective raincoat, couldn’t help but scold, "Didn’t you get the notice just now? You must wear protective rain gear when leaving indoors. Why didn’t you bring it?" He Bing was dumbfounded by the scolding. He had been in the First Outer City, concentrating on some gadgets by the light, when Li Hang abruptly pulled him away. "I... I was too hasty and forgot," He Bing said, a little confused. He felt that the corrosiveness of the acid rain was manageable—having just been out in it, he hadn’t felt any discomfort. "First go to the duty room and get a set of protective rain gear. Put it on first," Li Yu said somewhat exasperatedly, accompanying him to the duty room to put on the gear. Before his rebirth, he had grossly underestimated the perils of acid rain, and long exposure to it caused ulcers on the skin of his face and hands, followed by itching and swelling, and eventually nearly disfiguring him! In the post-apocalyptic world, the appearance of one’s face is not super critical, but it was a huge blow to Li Yu and made him become even more extreme later on. After the acid rain persisted for several days, he was dying of thirst in that basement, drank a lot of groundwater contaminated by acid rain, ended up with a burned throat, his voice became like a piece of torn cloth, and his stomach was affected. Occasional stomachaches afterwards were a consequence of that acid rain. Although he survived, being exposed to acid rain and drinking contaminated water left him with many sequelae. After his rebirth, he would never let such things happen again. The reservoir built at the foot of the mountain was to ensure that there would be a clean water source in the base during acid rain. Although with the equipment in the base now, they could distill pure water, it would consume too much energy and produce too little. ɪꜰ ʏᴏᴜ ᴡᴀɴᴛ ᴛᴏ ʀᴇᴀᴅ ᴍᴏʀᴇ ᴄʜᴀᴘᴛᴇʀs, ᴘʟᴇᴀsᴇ ᴠɪsɪᴛ NoveI★Fire.net