The Enemy Is Coming, and You Haven't Left the Solar System Yet?

Alien: "What? You haven't left your home planet for interstellar navigation yet!" Liu Xiaoyu: "..." Alien: "What? You haven't mastered controllable nuclear fusion yet!" Liu Xiaoyu: "..." Alien: "What? This planet does not have a unified political power, but it has more than 100 countries!" Liu Xiaoyu: "..." Alien: "You stupid carbon-based monkeys, my enemies are going to come knocking on my door soon, and you are still fighting among yourself." Liu Xiaoyu: "How soon will it be?" Aliens: "Ten Thousand Years"