论文部分内容阅读
一个人身上有密布全身的血管网。靠着这血管网,人才能把营养输送到肌体的各个部分,并把各部分产生的废物带回,然后通过肝、肾等器官将其分解、排泄出去,这样才能保持肌体的健康。如果血管出了栓塞、坏死等问题,扰会导致一部分肌体不能正常发挥其功能甚至坏死,严重时会导致人的死亡。国家的运输系统就好比是血管网,公路就是这运输系统的一个重要组成部分,高等级公路就是这一系统中的大动脉。有了这样的认识,公路,特别是高等级公路在国民经济中的重要性就凸现了出来。这就是我们国家每年都投入巨额资金建设公路的原因。
A person has a body network of blood vessels. With this network, people can deliver nutrition to all parts of the body and bring back the waste generated by each part, and then they can be decomposed and excreted through the organs such as the liver and the kidney so as to maintain the health of the body. If the blood vessels out of embolism, necrosis and other issues, interference will lead to some of the body can not function properly or even necrosis, severe cases can lead to human death. The national transport system is like a network of blood vessels, and the road is an important part of this transport system, and the high-grade road is the aorta in this system. With this understanding, the importance of highways, especially high-grade highways, in the national economy has come to light. This is why our country invests huge amounts of money each year in building roads.