话题原文：

中国的桥梁建设有着悠久的历史。中国古代桥梁以木材和石头为主要建筑材料,形式多样，极富特色。中国现存最古老的桥梁为隋代建造的安济桥，位于河北省赵县。安济桥又名赵州桥，桥长50.82米，桥宽9米，为国家重点保护的文物(cultural relic)。清朝末年，兰州黄河铁桥建成，标志着中国桥梁建设进入了以钢铁和混凝土(concrete)为主要材料的时期。如今，中国的桥梁建设保持着多项世界记录，中国跻身于世界桥梁建设强国行列。

参考译文:

China boasts a long history in bridge construction.With wood and stone as the major buildingmaterials, Chinese ancient bridges vary in forms andare highly distinct.Constructed in the Sui Dynasty,Anji Bridge, which is located in Zhao County, HebeiProvince, is the oldest existing bridge in China.Anji Bridge, also named Zhaozhou Bridge, is akey national protected cultural relic measuring a length of 50.82 meters and a width of 9meters.In the late years of the Qing Dynasty, Huanghe Iron Bridge in Lanzhou was completed,symbolizing that China's bridge construction stepped into an era of adopting steel andconcrete as the main materials for bridges.Now, bearing many world records, China standsamong world giants in bridge construction.

1.第二句中的“以...为主要建筑材料”可处理为状语，用介词短语with...as the major building materials表达，而“中国古代桥梁”宜译为“形式多样，极富特色”的主语，谓语部分“形式多样，极富特色”可处理为并列内容，用and连接，表达为vary in forms and are highly distinct。

2.第三句“中国现存最古老的桥梁…位于河北省赵县”的定语较多，可以拆译成两句。首先译出主要结构Anji Bridge is the bridge,“现存最古老的”有两个形容词，英语中的比较级或最高级形容词通常在其他形容词之前，故译为oldest existing。“隋代建造的”可处理为过去分词短语constructed in the Sui Dynasty 或which引导的定语从句。

3.第四句的主干是“安济桥为国家重点保护的文物”，故把“又名赵州桥”处理为插入语also named...;将“桥长50.82米，桥宽9米”处理为伴随状态的状语，用分词短语measuring a length of...and a width of...译出。

4.倒数第二句中的“兰州黄河铁桥”与“建成”之间是被动关系，翻泽时需把“建成”译为被动式wascompleted。“标志着中国…”是结果，故可处理为状语，用现在分词短语symbolizing that...表达。定语“以钢铁和混凝土为主要材料的”较长，可处理为后置定语，用现在分词短语adopting...as the main materials 表达，也可用介词短语with...as the main materials翻译。