bridge 600字高中英语作文
Bridge, is to each kind of bridge. Actually, according to the different use function, can be pided into "pedestrian bridge", "the car bridge", human overpasses and motorised vehicle constitutes urban highway system "interchange viaduct" and so on.
The structure of the bridge, with the rapid development of science and technology and industrial production is also in the development and change constantly. Now has a beam bridge structure, steel structure bridge, suspension bridge structure, suspension bridge structure, and so on many kinds of.
The structure of the bridge, with the rapid development of science and technology and industrial production is also in the development and change constantly. Now has a beam bridge structure, steel structure bridge, suspension bridge structure, suspension bridge structure, and so on many kinds of.
The shape of the bridge is various, the style each different. Pedestrian bridge generally have one word, T word, cross, S, Y, U, all the amorphous, according to the topography and flexible design. Dealership bridge basic types of diamond, alfalfa, ring type, horn, etc. In short, as long as the function, structure and shape perfectly together, can achieve good effect of art and technology.The bridge in the city, not only is a sign of prosperity in cities, more major is it in the aspects of urban transportation, energy, benefit play a huge role. With Shanghai yanan east road pedestrian bridge as an example, after the commissioning of the bridge, the bridge nearby within 100 meters of motor vehicle speed increased by 28%, compared with the previous and a 80% drop in traffic accidents and its economic benefit and social benefit is obvious. Since 1964 in guangzhou to build the first overpass in China, Beijing, Shanghai, tianjin, guangzhou and other major cities are built by all kinds of intersection has reached thousands of, in the aspects of urban transportation, energy, benefit plays a huge role.
Reveal an avalanche
One day in February 1999, several skiers downwards along the slope to slide to the snow against their natural and unrestrained, like in the snow flutters the swallow. Suddenly, the sound "click" sound, followed by a mass of snow fog down from behind, quickly buried them. They startled from the narcissism: an avalanche! But everything is too late...
Snow fog rolled up rushing forward, they rushed up the snow together along the acceleration ran down the hill, running snow more and more, faster and faster, with the way the forest zone of trying to stop the rush of snow, but almost all the trees and the snow flow desolately broken. After forest belt is some residents housing, residents have no time to leave the house, together with the house be running snow swept away. 4 km along the narrow strip of a mess, trees, villages and farmland, electrical,... There is no escape.
The avalanche of up to 250 km per hour, with the energy can achieve a l05 l04 mega joule. If it meets people unfortunately, the impact of the nipples can only be equivalent to 15 tons of run over by a truck on the body.
The occurrence of avalanche seems quite by chance, when it occurs, in what place, it is difficult to grasp. It is like a snowflake fall to the ground, or larger voice can trigger an avalanche in the mountain, the Alps are likely to be an avalanche of skiers disturb the peace of the heavy snow, thus caused the sudden disaster.
