Building a Bridge
美音、自然拼读、分级阅读与词汇复习
Bridges go over rivers and lakes.
桥通于江湖.
They go over bays and swamps.
它们穿过海湾和沼泽
They go over highways and railroads.
他们穿过了高速公路和铁路。
Some even float.
一些甚至漂浮着。
Bridges are long and short.
大桥长而短.
They can be high above the water.
其能高于水上.
They can be near the water.
它们可能在水边
They can carry cars, trucks, trains, and buses.
他们可以搭载汽车,卡车,火车,以及巴士.
Some carry people.
有些人背着人
Some carry water or oil.
有些携带水或油.
The first bridges were made out of wood, rope, or stone.
最早的桥梁是用木头,绳子,或用石头所造.
Today, most bridges are made of steel and concrete.
如今,大多数桥梁由钢筋混凝土所建.
The first bridges were simple.
最初的桥梁很简单。
Some were just logs placed across a stream.
有些只是放在溪边的木头
Some were ropes stretched across a river.
有些是绳子被拉过一条河
Later, stones were used to build stronger and longer bridges.
后来用石头来建造更坚固更长的桥梁.
In time, people were building bridges like the ones we see today.
随着时间的推移,人们正在建造像我们今天看到的桥梁。
These are made of concrete and steel.
这些由混凝土和钢制成.
They go across longer distances.
他们走的更远。
There are names for different types of bridges.
不同种类的桥梁都有取名.
This table shows some of the types.
本表列出部分类型.
Building bridges is a big job.
修桥是件大事
It can take many years.
这可能需要很多年。
It can cost millions of dollars.
它可能花费上百万美元。
It can take many workers to build a bridge.
建造一座桥需要许多工人。
Let’s look at a bridge being built over a river.
让我们看看一条河上的桥梁。
First, workers must build supports under the water.
第一,工人必须在水下建立支撑。
They hammer large steel tubes into the river bottom.
他们把大钢管打入河底
The tubes, called piles, are filled with concrete.
管子被混凝土填满,称为"堆".
Next, workers put supports across the piles.
接下来,工人把支撑 跨出堆积。
The supports are built under water using a special dam.
支撑用特大坝在水下建造.
A dam holds the water back.
一个大坝挡住水面
The workers can work where it is dry.
工人可以在干燥的地方工作。
Next, workers build piers.
接下来是工人建造码头.
They are like the legs on a table.
他们就像桌子上的腿一样
They will hold up the bridge.
他们会撑起桥的
Then caps are put on the tops of the piers.
然后将盖子放入码头上.
Concrete pieces, called girders, are put between two piers.
混凝土块被叫作" gi",被放入两个码头之间.
The girders hold up the roadway.
gi者以道为起.
Steel bars are placed between the girders.
钢筋被放置在被子之间.
The steel bars make the concrete stronger.
钢筋使混凝土更坚固.
Concrete is poured over the steel bars.
混凝土倒在钢筋上
The concrete gets hard.
混凝土变硬了
Finally, the new bridge is ready for traffic.
最后,新桥通车.