I want to find a novel that I have read before. The protagonists are all from China. It seems that they all go abroad to learn about hydropower stations.

Isaac asimov, the most famous contemporary American popular science writer, science fiction writer and the world's top science fiction writer, has a brief introduction to the base trilogy: the base trilogy: the base is the first in the base trilogy. The galactic empire that ruled the galaxy 12000 has gradually declined. At that time, there was only Harry, the great master of psychohistory? Seldon foresaw that people in the galaxy would experience a dark period of 30,000 years, full of ignorance, barbarism and war. Seldon then managed to set up a "base" on a desolate planet on the edge of the Milky Way, hoping that it would become a beacon of hope for future generations of mankind. However, with the gradual decline of the empire, the base was surrounded by militant strong neighbors. Humans are also faced with painful choices, surrendering to barbaric forces and willing to be controlled? Or stand up and fight regardless of the danger of being wiped out? The base series trilogy: Base and Empire and Base and Empire is the second part of the base series trilogy. At this time, the base founded by hari seldon, a great psychological historian, has gained a firm foothold in the outer edge of the galaxy, but it still has to face the pressure from the galactic empire. The dying empire still has the most powerful power in the galaxy. An ambitious general led a space fleet to attack the base, and scholars and scientists living on the base asteroid hoped to escape this catastrophe, which was maintained by the language left by Seldon before his birth ... However, even Seldon could not have predicted that there was an external force more threatening than the space corps, and that was the mutant "mule" in the Milky Way. In the face of the strange spiritual power of mules, no matter how strong people are, they will be obedient slaves. Mule Black Fleet has accepted the history of more than 300 years without bloodshed. In order to conquer the universe, mules and loyal people are looking for the second base. The first wave of search of mules is stopped by an ordinary woman, Bei Da, thus winning enough time for the counterattack plan of the second base. Trilogy of Base Series: Second Base Second Base is the third in the trilogy of "Base" series. The existence of the mysterious second base has become the target of public criticism. The mule wants to eradicate it, and the immigrants at the first base must find it for completely different reasons, but where is it? This story is the legend of the parties looking for the second base. Mules tried their best to find and eradicate the second base, but failed. Later, the base personnel also tried their best to find a second base because they didn't want to hand over the achievements of building a new empire. No one expected that the net rope he was looking for was actually maintained on a little girl. Oh, one more thing. The ABC Tianbian oral English teacher who helped me a few days ago made me understand that learning English well is actually very easy ~ the appropriate learning situation and the level of foreign teachers who are learning oral English are very important. Only when your oral English is pure can you keep practicing oral English every day. 1 tutoring 1 will make great progress and efficiency ... Remember to review and listen to the classroom recording files after the course to help strengthen your memory. If there is really nothing to practice, then go to Cocoa or Aisina to practice speaking, practicing, asking, listening and reading more, and the unconscious sense of language will be strengthened, and the learning effect will definitely advance by leaps and bounds. Fourteen-year-old Agatha was scared to death. What secret did she discover about the second base?