完成一倍有效流水怎么算

简介：First at the South Gate, then at the West Gate, and then at the East Gate and North Gate, tens of thousands of Kaifeng defenders and hundreds of thousands of Kaifeng people cheered in unison. Everyone knew that the bandits wanted to blow up the city, but failed. Kaifeng is a city. A city blessed by gods can never be captured by bandits.