Big Machines

Big Machines, written by Brian Roberts.

《大型机械》，作者：布莱恩·罗伯茨。

Introduction. Work is done when something is moved from one place to another. Machines are used to do the work. They move things from one place to another. Some things are easy to move. Other things are not.

引言。 当我们把物品从一个地方搬到另一个地方时，就是在完成工作。 机械就是用来帮我们做这些工作的。 它们负责把物品从一个地方运到另一个地方。 有些东西搬起来很容易。 有些东西就很难搬动啦。

Small machines are used for smaller jobs. Things like shovels are simple machines. They do not have many moving parts.

小型机械用来完成比较小的工作。 像铲子这类物品就属于简单机械。 它们没有太多可活动的零件。

Big machines are used to move heavy things. They are used to build tall buildings. They are used to build roads and bridges. They are used to take resources from the earth.

大型机械用来搬运很重的物品。 人们用它们来建造高高的楼房。 也用它们来修建道路和桥梁。 还能用它们从地下开采资源。

Building tall buildings. It takes many big machines to build a tall building. Large power shovels called excavators dig deep holes in the ground. Some power shovels have huge buckets that can scoop a swimming pool sized pile of dirt in one scoop. Others have clam -like buckets that take big bites out of the earth.

建造高楼。 建造一栋高楼需要用到很多大型机械。 有一种叫做挖掘机的大型动力铲，能在地面挖出深深的坑洞。 有些动力铲配有巨大的铲斗，一铲就能挖走和游泳池体积一样大的一堆泥土。 还有些动力铲配有蛤壳状的铲斗，能大口大口地挖走泥土。

Bulldozers are machines that move the dirt around. Giant dump trucks carry the dirt away. Concrete trucks carry concrete to the worksite. Flatbed trucks carry steel beams and rods to the worksite. Large cranes lift steel beams into place. They also carry buckets of concrete to workers high above ground.

推土机是用来挪动泥土的机械。 巨型自卸卡车负责把泥土运走。 混凝土搅拌车把混凝土运送到工地。 平板卡车把钢梁和钢筋运送到工地。 大型起重机把钢梁吊到对应的位置。 它们还会把一桶桶混凝土送到高空作业的工人手里。