On the Political Analysis of Postgraduate Entrance Examination in 2006

Once upon a time, there was a temple on the bank of the canal. One year, the canal suddenly overflowed and the temple was washed away by the flood. A pair of mighty stone lions in front of the temple also rolled into the water with the flood. Ten years later, with the help of the local people, the monks of the temple decided to rebuild the temple. Their first thought was to find the stone lions washed away by the flood and put them in front of the temple. However, for more than ten years, the river has been turbid and rushing all day. Where can I find it? Some people say that the stone lion is too heavy. It must have sunk in the river near the temple. So, a group of people were organized to salvage it, but it took a long time to salvage it, and it was not salvaged. Others said: The river flows downstream, and I'm afraid the stone lion was washed downstream by the river. People happily dispatched several boats, holding iron rakes and combing their hair. From top to bottom, from left to right, they searched for more than ten miles of land, but they still couldn't find it downstream. At this time, an old gentleman who taught in the temple said to the fishermen, "You really don't understand! The stone lion is strong and heavy, and it will only sink deeper and deeper if it is submerged in the sand. It must be the same place where the temple was washed. How do you look downstream? " After listening to the old gentleman's words, everyone felt very reasonable and dug up the collapsed temple with confidence. At this time, an old river worker guarding the river bank came over and said to everyone, "Hey, you are digging stone lions in situ! Hey, you just can't dig a few feet underground, you have to look upstream. " Hearing this, the teacher shook his head again and again and said, "Nonsense, nonsense" and walked away. Everyone also took the old river worker's words as a joke, thinking that the stone lion was so heavy, how could it climb upstream? Seeing that everyone didn't listen to his advice, the old river worker didn't say a word, propped up the boat and rowed upstream. It took only a little effort to find the pair of stone lions in the upper reaches not far from the ruins of the old temple. This discovery greatly surprised people. Everyone gathered around the old river worker and asked him how he knew the Shishi would be upstream. The old river worker smiled and said, "I have been dealing with river sand for forty or fifty years, but I still can't figure out his temper." The stone lion turned over, turned over. "Why did the Shishi turn upside down when it reached the upstream? As the saying goes, "if a stone is thrown into the river, it must be found from the upstream." "It turns out that the stone lion is strong and thick, and the river sand is loose and frivolous. The water coming down from the upstream can't reach the stone lion, so it is called the first gear of the stone lion and rushes back to both sides. In this way, the sand under the stone lion was constantly swept away, and a pit was slowly rushed out under the stone lion. The pit became bigger and bigger, and the stone lion gradually lost its balance. Because its center of gravity was backward, it fell into the pit behind. The running water washed away the sand under the stone lion again, and the stone lion fell into the pit behind. In this way, like a somersault, over time, the stone lion suddenly went upstream. Let's feel the "fishing for iron cows" in primary school textbooks. During the Song Dynasty, the Yellow River flooded and a pontoon bridge outside the city was washed away. Eight iron cows on both sides of the Yellow River were used to tie pontoons. They were also washed away by the flood and trapped in the mud at the bottom of the river. The flood receded and the pontoon bridge had to be rebuilt. But the heavy iron cow was trapped at the bottom of the river. Which Hercules can catch them one by one? People are talking about it. A monk said, "Let me try. The iron cows were washed away by the water, so I asked the water to send them back. "The monk first asked people familiar with water to dive to the bottom and find out where the eight iron cows sank. Then prepare two big wooden boats, the cabins of which are filled with sediment, and row them to the place where the iron cow sank. When the boat stopped, he had two boats tied side by side tightly and put up a shelf with strong wood to straddle the two boats. Please also ask people who are familiar with water to dive to the bottom with a thick rope. One end of the rope is firmly tied to the iron cow, and the other end is tied to the shelf between the two big ships. The preparations have been completed. The monk asked the sailors, Qi Xin, to work together to shovel all the sediment from the ship into the Yellow River. The sediment in the boat slowly decreased, the boat slowly floated up, and the rope that tied the iron cow became tighter and tighter. Relying on the buoyancy of the water, the ship pulled the iron cow up from the mud bit by bit. The sand on the boat was shoveled away and the iron cow left the bottom of the river. The monk was not in a hurry to get the iron cow into the boat, but let the sailors row the boat to the shore hard, and then let many people drag the iron cow into the water together. In this way, the monk dragged eight heavy iron cows back one by one. This monk named Huai Bing was an outstanding engineer at that time. The reason is that the stone blocks the water, and the water forms a vortex to take away the sand under the stone, forming a pit under the stone, and then the stone will roll back and so on, and continue to go upstream.