土木工程专业英语LESSON7课件.ppt

§ Lesson7 Bridge ; Bridge is a structure that spans obstacles, such as rivers and valleys, to provide a roadway for traffic. By far the majority of bridges are designed to carry automobile or railroad traffic, but some are intended for pedestrians only. pedestrian? ? noun a person walking along a road or in a built-up area 步行者，行人 adjective lacking inspiration or excitement; dull缺乏想像力的，平淡无奇的，乏味的; A number of aqueduct bridges, mostly erected in Europe in the 19th century, carry canals and their barge traffic; and at least one bridge, at New York City’s Kennedy Airport, serves to carry taxying aircraft over a highway. aqueduct bridge? ? 高架水渠 verb (taxis, taxied, taxiing or taxying) (intransitive) (of an aircraft) move slowly along the ground before takeoff or after landing: the plane taxis up to a waiting car . take a taxi as a means of transport: I would taxi home and sleep till eight. 大量的高架渠桥于19世纪在欧洲建成，以保证运河和船舶交通的运行。最小的一座桥在纽约市的肯尼迪机场，它主要是把滑行飞机拖到跑道上服务的。;The first bridges built by man probably resembled those still being constructed by primitive peoples in isolated regions. primitive? adj. 原始的, 早期的简单的; 粗糙的原始人, 原始事物 人类建成的首批桥类似于原始人在孤立地带建成的桥。 The tools and building skills of early man, like those of primitive peoples today, were so elementary that he was undoubtedly forced to use easily transportable materials that could be put in place with a minimum of forming and shaping. 早期人类的工具和建筑技术如同原始人类一样都是最初级的，只有应用经过简单加工成型的材料。 ; In forest regions, where stout timbers or logs could be obtained, bridges very likely were made of one more parallel logs, possibly covered with cross branches or matting for better footing. stout结实的；厚实的 在森林里，随处可得结实的木材，那时侯的桥极可能是由并排的几根圆木建成，可能在其上覆一些木枝或草垫以方便行走。 ; In tropical regions of India, Africa, and South America, fibrous vines were used to build suspension bridges. The vines were tied to trees or rocks on each side of the stream or valley to be crossed. One or more vines were used to tread on. Othe