完成一倍有效流水怎么算

简介：Day and night alternate, the stars and rivers rotate, the tides rise and fall, the moon and the sun rise and set. After flying over the sea for several days, an emerald-like beautiful archipelago appeared outside the airship's port window. There are many mountains on the island, and the mountains are dotted with lakes of various sizes, like the pearls scattered by the goddess of the sea.