47 Which of the following materials have NOT been used as cables for suspension bridges?
(A) Iron.
(B) Wood.
(C) Steel.
(D) Vines.

A suspension bridge is a type of bridge that use overhead cables to support its roadway.

吊橋是一種使用架空電纜支撐其道路的橋樑。

The design of a suspension bridge is simple and straightforward, and uses several architectural techniques to distribute the weight of the bridge safely and evenly.

懸索橋的設計簡單直接，並採用多種建築技術安全均勻地分配橋樑的重量。

The construction of a suspension bridge starts with its towers, which are usually located on dry land and anchored to bedrock.

懸索橋的建造始於其塔樓，塔樓通常位於陸地上並固定在基岩上。

Once the towers are built, master cables are strung across them and anchored into the bank at both ends of the bridge.

一旦塔架建成後，主電纜穿過它們，並錨定在橋兩端的岸上。

Next, suspension cables are strung from the master cables, and then the deck used as roadway is attached to them.

接下來，從主電纜串起懸掛電纜，然後將用作道路的甲板連接到它們上。

Most of the weight of the bridge is transferred by the cables to the anchorage systems.

橋樑的大部分重量都通過電纜傳輸到錨固系統。

These are embedded in either solid rock or huge concrete blocks.

這些嵌入固體岩石或巨大的混凝土塊。

Inside the anchorages, the cables are spread over a large area to evenly distribute the load and to prevent the cables from breaking free.

在錨地內部，電纜鋪設在大面積上以均勻分佈負載並防止電纜斷裂。

One of the oldest engineering forms, suspension bridges were constructed by primitive peoples using thick vines for cables.

最古老的工程形式之一，懸索橋是由原始民族用電纜的厚藤建造的。

A much stronger type was introduced in India around 400 A.D. that used cables of braided bamboo.

印度大約在400年前引入了一種更強大的類型，它使用編織竹子的電纜。

In the early nineteenth century, suspension bridges used iron chains for cables.

在十九世紀初期，懸索橋使用鐵鍊作為電纜。

Today, the cables are made of thousands of individual steel wires bound tightly together.

今天，電纜由數千根緊密結合在一起的單根鋼絲製成。

A single steel wire, only 0.1 inch thick, can support over half a ton of weight without breaking.

只有0.1英寸厚的單根鋼絲可以支撐半噸以上的重量而不會斷裂。

Light and strong, a suspension bridge could span distances from 2,000 to 7,000 feet, which is much longer than any other kind of bridge could.

輕而堅固的懸索橋可以跨越2000至7000英尺的距離，比任何其他類型的橋樑都長得多。

Its simple design allows high clearance under the deck, useful when the bridge is built over a major shipping waterway or a very deep gulf.

其簡單的設計允許在甲板下高度清理，當橋樑建在主要航運航道或非常深的海灣時非常有用。

A suspension bridge is also less subjected to collapse than some other bridge types such as those built on support pillars

與其他一些橋樑類型（如建立在支柱上的橋樑類型）相比，懸索橋也較少受到坍塌

suspension /səsp'ɛnʃən/  懸掛,暫停,中止 

overhead  /'ovɚh'ɛd/  經常開支,普通用費(a.)在頭上的,高架的(ad.)在頭頂上,在空中,在高處

straightforward /str'etf'ɔrwɚd/   (a.)筆直的,率直的,粗獷的,明確的,簡單的,直接的

architectural  /,ɑrkət'ɛktʃɚəl/  (a.)建築的,建築學的,建築術的

distribute /dɪstr'ɪbjut/ (vt.)分配,分發,分佈,散佈,分類

evenly  /'ivənli/ (ad.)平衡地,平坦地,平等地

anchored /'æŋkɚd/拋錨 ;固定

bedrock  /b'ɛdr,ɑk/  岩床,根底,基礎

strung  /str'ʌŋ/   (vbl.)string的過去式和過去分詞 字串,細繩,索,帶子;一串,一行,一列(v.)縛,紮,穿,串起,排成一列

deck /d'ɛk/ 紙牌背面圖案甲板,覆蓋物(vt.)裝飾,打扮裝甲板

 attach  /ət'ætʃ/    (vt.)使…附屬於…,把…附加在…,系上,縛上,使依附; 附加; 附接; 連接

anchorage /'æŋkɚədʒ/ 下錨,停泊所,停泊稅

primitive  /pr'ɪmətɪv/ 原始人,早期藝術家(a.)原始的,上古的,舊式的

vine /v'ɑɪn/ 攀爬植物,藤,蔓,葡萄樹(vi.)形成蔓藤

braid /br'ed/ 辮子,穗帶(vt.)編成辮,鑲邊

wire /w'ɑɪɚ/  電線,電報,電信,鐵絲網,金屬絲(vt.)用金屬絲卷起,拍電報(vi.)打電報

bound /b'ɑʊnd/    躍,回跳,範圍,邊界(a.)受約束的,裝訂的,有義務的,關聯的,被束縛的

clearance /kl'ɪrəns/ 清除,解除,間隙,森林開拓

ship  /ʃ'ɪp/  船,艦(vt.)以船運送,裝船,運送(vi.)上船,乘船

gulf /g'ʌlf/  海灣,深淵,漩渦,隔閡(vt.)吞沒

pillar  /p'ɪlɚ/ 柱子,支柱,台柱,紀念柱,棟梁