Moving Bridges

Moving Bridges, written by Anthony Curran. Focus Question. How and why do bridges move?

《可移动桥梁》，作者安东尼·柯伦。 核心问题 桥梁是怎么移动的？又为什么要移动呢？

Draw bridges were the first moving bridges. They were built to help defend castles. The bridges could be raised to keep attackers away.

吊桥是最早的可移动桥梁， 建造它们是为了帮助防御城堡。 人们可以把吊桥升起来，把进攻的敌人挡在外面。

Today, bridges over rivers move to let ships pass by safely. There are many different types of bridges that move.

如今，河上的桥梁会移动，是为了让船只能够安全通过。 可移动的桥梁有很多不同的种类哦。

Some bridges tilt up to open on one side. Some bridges have two pieces tilt up to open in the middle.

有些桥梁会向上翘起，从单侧打开。 有些桥梁有两段桥身，会向上翘起从中间打开。

Some bridges fold up, like an accordion.

有些桥梁可以像手风琴一样折叠起来。

Some bridges have a middle part that turns to make space on either side.

有些桥梁的中间部分会转动，在桥的两侧都腾出空间。